SELECT BE.DETAIL_TEXT as DETAIL_TEXT, BE.DETAIL_PICTURE as DETAIL_PICTURE,BE.ID as ID,BE.IBLOCK_ID as IBLOCK_ID,BE.IBLOCK_SECTION_ID as IBLOCK_SECTION_ID,BE.NAME as NAME,IF(EXTRACT(HOUR_SECOND
FROM
BE.ACTIVE_FROM)>0, DATE_FORMAT(BE.ACTIVE_FROM, '%d.%m.%Y %H:%i:%s'), DATE_FORMAT(BE.ACTIVE_FROM, '%d.%m.%Y')) as ACTIVE_FROM,DATE_FORMAT(BE.TIMESTAMP_X, '%d.%m.%Y %H:%i:%s') as TIMESTAMP_X,B.DETAIL_PAGE_URL as DETAIL_PAGE_URL,B.LIST_PAGE_URL as LIST_PAGE_URL,BE.DETAIL_TEXT_TYPE as DETAIL_TEXT_TYPE,BE.PREVIEW_TEXT as PREVIEW_TEXT,BE.PREVIEW_TEXT_TYPE as PREVIEW_TEXT_TYPE,BE.PREVIEW_PICTURE as PREVIEW_PICTURE, 
FPS0.*,

L.DIR as LANG_DIR,BE.CODE as CODE,
BE.XML_ID as EXTERNAL_ID,B.IBLOCK_TYPE_ID as IBLOCK_TYPE_ID,B.CODE as IBLOCK_CODE,B.XML_ID as IBLOCK_EXTERNAL_ID,B.LID as LID
FROM
b_iblock B
INNER JOIN b_lang L ON B.LID=L.LID
INNER JOIN b_iblock_element BE ON BE.IBLOCK_ID = B.ID
INNER JOIN b_iblock_element_prop_s15 FPS0 ON FPS0.IBLOCK_ELEMENT_ID = BE.ID
WHERE
1=1 AND ( ((((BE.IBLOCK_ID = '15')))) AND (EXISTS ( SELECT IBLOCK_ID
FROM
b_iblock_site
WHERE
IBLOCK_ID = B.ID AND (((SITE_ID='1a'))) )) AND ((((BE.ACTIVE='Y')))) AND (((BE.ACTIVE_TO >= now() OR BE.ACTIVE_TO IS NULL) AND (BE.ACTIVE_FROM <= now() OR BE.ACTIVE_FROM IS NULL))) AND ( ( (( EXISTS ( SELECT BSE.IBLOCK_ELEMENT_ID
FROM
b_iblock_section_element BSE
INNER JOIN b_iblock_section BS ON BSE.IBLOCK_SECTION_ID = BS.ID
WHERE
BSE.IBLOCK_ELEMENT_ID = BE.ID AND ((BS.CODE IN ('form_71649'))) ))) ) OR ( ( (( EXISTS ( SELECT BSE.IBLOCK_ELEMENT_ID
FROM
b_iblock_section_element BSE
INNER JOIN b_iblock_section BS ON BSE.IBLOCK_SECTION_ID = BS.ID
WHERE
BSE.IBLOCK_ELEMENT_ID = BE.ID AND ((BS.CODE IN ('common_news'))) ))) ) ) ) ) AND (((BE.WF_STATUS_ID=1 AND BE.WF_PARENT_ELEMENT_ID IS NULL)))
ORDER BY BE.ACTIVE_FROM desc

1	PRIMARY	B	const	PRIMARY	PRIMARY	4	const	1	Using temporary; Using filesort
1	PRIMARY	L	const	PRIMARY	PRIMARY	6	const	1	
1	PRIMARY	FPS0	ALL	PRIMARY				47751	Using where
1	PRIMARY	BE	eq_ref	PRIMARY,ix_iblock_element_1,ix_iblock_element_4,ix_iblock_element_3,ix_iblock_element_code	PRIMARY	4	government.FPS0.IBLOCK_ELEMENT_ID	1	Using where
4	DEPENDENT SUBQUERY	BSE	ref	ux_iblock_section_element,UX_IBLOCK_SECTION_ELEMENT2	UX_IBLOCK_SECTION_ELEMENT2	4	government.BE.ID	1	
4	DEPENDENT SUBQUERY	BS	eq_ref	PRIMARY	PRIMARY	4	government.BSE.IBLOCK_SECTION_ID	1	Using where
3	DEPENDENT SUBQUERY	BSE	ref	ux_iblock_section_element,UX_IBLOCK_SECTION_ELEMENT2	UX_IBLOCK_SECTION_ELEMENT2	4	government.BE.ID	1	
3	DEPENDENT SUBQUERY	BS	eq_ref	PRIMARY	PRIMARY	4	government.BSE.IBLOCK_SECTION_ID	1	Using where
2	DEPENDENT SUBQUERY	b_iblock_site	const	PRIMARY	PRIMARY	10	const,const	1	Using index

1	PRIMARY	B	const	PRIMARY	PRIMARY	4	const	1	
1	PRIMARY	L	const	PRIMARY	PRIMARY	6	const	1	
1	PRIMARY	FPS0	ALL	PRIMARY				47751	Using where
1	PRIMARY	BE	eq_ref	PRIMARY,ix_iblock_element_1,ix_iblock_element_4,ix_iblock_element_3,ix_iblock_element_code	PRIMARY	4	government.FPS0.IBLOCK_ELEMENT_ID	1	Using where
4	DEPENDENT SUBQUERY	BSE	ref	ux_iblock_section_element,UX_IBLOCK_SECTION_ELEMENT2	UX_IBLOCK_SECTION_ELEMENT2	4	government.BE.ID	1	
4	DEPENDENT SUBQUERY	BS	eq_ref	PRIMARY	PRIMARY	4	government.BSE.IBLOCK_SECTION_ID	1	Using where
3	DEPENDENT SUBQUERY	BSE	ref	ux_iblock_section_element,UX_IBLOCK_SECTION_ELEMENT2	UX_IBLOCK_SECTION_ELEMENT2	4	government.BE.ID	1	
3	DEPENDENT SUBQUERY	BS	eq_ref	PRIMARY	PRIMARY	4	government.BSE.IBLOCK_SECTION_ID	1	Using where
2	DEPENDENT SUBQUERY	b_iblock_site	const	PRIMARY	PRIMARY	10	const,const	1	Using index

explain SELECT 
BE.DETAIL_PICTURE as DETAIL_PICTURE,BE.ID as ID,
BE.IBLOCK_ID as IBLOCK_ID,BE.IBLOCK_SECTION_ID as IBLOCK_SECTION_ID,
BE.NAME as NAME,IF(EXTRACT(HOUR_SECOND
FROM
BE.ACTIVE_FROM)>0, DATE_FORMAT(BE.ACTIVE_FROM, '%d.%m.%Y %H:%i:%s'), DATE_FORMAT(BE.ACTIVE_FROM, '%d.%m.%Y')) as 
ACTIVE_FROM,DATE_FORMAT(BE.TIMESTAMP_X, '%d.%m.%Y %H:%i:%s') as TIMESTAMP_X,B.DETAIL_PAGE_URL as DETAIL_PAGE_URL,
B.LIST_PAGE_URL as LIST_PAGE_URL,BE.DETAIL_TEXT as DETAIL_TEXT,BE.DETAIL_TEXT_TYPE as DETAIL_TEXT_TYPE,BE.PREVIEW_TEXT as PREVIEW_TEXT,
BE.PREVIEW_TEXT_TYPE as PREVIEW_TEXT_TYPE,BE.PREVIEW_PICTURE as PREVIEW_PICTURE,
 /*отметка */ FPS0.*, 
 L.DIR as LANG_DIR,BE.CODE as CODE,BE.XML_ID as EXTERNAL_ID,B.IBLOCK_TYPE_ID as IBLOCK_TYPE_ID,B.CODE as IBLOCK_CODE,
 B.XML_ID as IBLOCK_EXTERNAL_ID,B.LID as LID
FROM
b_iblock B
INNER JOIN b_lang L ON B.LID=L.LID
INNER JOIN b_iblock_element BE ON BE.IBLOCK_ID = B.ID
/* отметка */INNER JOIN b_iblock_element_prop_s15 FPS0 ON FPS0.IBLOCK_ELEMENT_ID = BE.ID     
WHERE
1=1 AND ( ((((BE.IBLOCK_ID = '15')))) AND (EXISTS ( SELECT IBLOCK_ID
FROM
b_iblock_site
WHERE
IBLOCK_ID = B.ID AND (((SITE_ID='1a'))) )) AND ((((BE.ACTIVE='Y')))) AND 
(((BE.ACTIVE_TO >= now() OR BE.ACTIVE_TO IS NULL) AND (BE.ACTIVE_FROM <= now() OR BE.ACTIVE_FROM IS NULL))) AND 
( ( (( EXISTS ( SELECT BSE.IBLOCK_ELEMENT_ID
FROM
b_iblock_section_element BSE
INNER JOIN b_iblock_section BS ON BSE.IBLOCK_SECTION_ID = BS.ID
WHERE
BSE.IBLOCK_ELEMENT_ID = BE.ID AND ((BS.CODE IN ('form_71649'))) ))) ) OR ( ( (( EXISTS ( SELECT BSE.IBLOCK_ELEMENT_ID
FROM
b_iblock_section_element BSE
INNER JOIN b_iblock_section BS ON BSE.IBLOCK_SECTION_ID = BS.ID
WHERE
BSE.IBLOCK_ELEMENT_ID = BE.ID AND ((BS.CODE IN ('common_news'))) ))) ) ) ) ) AND (((BE.WF_STATUS_ID=1 AND BE.WF_PARENT_ELEMENT_ID IS NULL)))
ORDER BY
BE.ACTIVE_FROM desc

explain 
select b_iblock_element.*, b_iblock_element_prop_s15.*
from b_iblock_element
INNER JOIN b_iblock_element_prop_s15 ON b_iblock_element_prop_s15.IBLOCK_ELEMENT_ID = b_iblock_element.ID

explain 
select b_iblock_element_prop_s15.IBLOCK_ELEMENT_ID
from b_iblock_element
INNER JOIN b_iblock_element_prop_s15 ON b_iblock_element_prop_s15.IBLOCK_ELEMENT_ID = b_iblock_element.ID

explain 
select b_iblock_element_prop_s15.*
from b_iblock_element
INNER JOIN b_iblock_element_prop_s15 ON b_iblock_element_prop_s15.IBLOCK_ELEMENT_ID = b_iblock_element.ID

explain
select b_iblock_element.*
from b_iblock_element
INNER JOIN b_iblock_element_prop_s15 ON b_iblock_element_prop_s15.IBLOCK_ELEMENT_ID = b_iblock_element.ID