'Limit  (cost=0.00..6951.71 rows=500 width=257) (actual time=341.149..2999.962 rows=500 loops=1)'
'  ->  Nested Loop  (cost=0.00..712119.47 rows=51219 width=257) (actual time=341.147..2999.824 rows=500 loops=1)'
'        ->  Index Scan using type_ts_cashier on pos_events  (cost=0.00..296952.83 rows=51219 width=136) (actual time=288.904..766.576 rows=500 loops=1)'
'              Index Cond: ((event_type = 300) AND (event_ts_received >= 1202118750621000::bigint) AND (event_ts_received <= 1393926750621000::bigint) AND (lower(event_cashier_name) = '???°N?N?N?????????N? ??????N???N???N? ?????????»?°?µ?????°'::text))'
'        ->  Index Scan using pos_receipts_pkey on pos_receipts  (cost=0.00..7.84 rows=1 width=121) (actual time=1.970..1.985 rows=1 loops=500)'
'              Index Cond: ((receipt_id)::text = (pos_events.event_receipt_id)::text)'
'Total runtime: 3000.123 ms'

CREATE TABLE pos_receipts
(
  receipt_id character varying(128) NOT NULL,
  -- много других полей
  CONSTRAINT pos_receipts_pkey PRIMARY KEY (receipt_id )
)

CREATE TABLE pos_events
(
  event_ts_received bigint NOT NULL,
  event_type integer NOT NULL,
  event_cashier_name text NOT NULL,
  event_receipt_id character varying(128) NOT NULL,
  -- много других полей
  CONSTRAINT pos_events_pkey PRIMARY KEY (event_ts_received ),
  CONSTRAINT pos_events_event_receipt_id_fkey FOREIGN KEY (event_receipt_id)
      REFERENCES pos_receipts (receipt_id) MATCH SIMPLE
      ON UPDATE NO ACTION ON DELETE CASCADE
)

CREATE INDEX events_receipts_idx
  ON pos_events
  USING btree
  (event_receipt_id COLLATE pg_catalog."default" );

CREATE INDEX type_ts_cashier
  ON pos_events
  USING btree
  (event_type , event_ts_received , lower(event_cashier_name) COLLATE pg_catalog."default" );

SELECT *
FROM pos_events INNER JOIN pos_receipts ON pos_events.event_receipt_id = pos_receipts.receipt_id
WHERE TRUE
AND event_ts_received >= 1202118750621000
AND event_ts_received <= 1393926750621000
AND event_type IN (300)
AND lower(event_cashier_name) = lower('Мартынович Виктория Николаевна')
ORDER BY event_ts_received ASC 
LIMIT 500

CREATE INDEX type_ts_cashier
  ON pos_events
  USING btree
  (event_type , lower(event_cashier_name) COLLATE pg_catalog."default" , event_ts_received );