SELECT 
  o0_.aoid AS aoid0, 
  o0_.aoguid AS aoguid1, 
  o0_.formalnamepath AS formalnamepath2, 
  o0_.regioncode AS regioncode3, 
  o0_.aolevel AS aolevel4, 
  o0_.actstatus AS actstatus5 
FROM 
  object_name o0_ 
WHERE 
  o0_.regioncode = ? AND o0_.formalnamepath = ? 
LIMIT 
  1

QUERY PLAN
Limit (cost=0.00..135.20 rows=1 width=203)

-> Result (cost=0.00..540.80 rows=4 width=203)

-> Append (cost=0.00..540.77 rows=4 width=203)

-> Seq Scan on addrobj (cost=0.00..0.00 rows=1 width=466)

Filter: ((actstatus = 1) AND ((regioncode)::text = '77'::text) AND (aolevel = ANY ('{1,4,6}'::bigint[])) AND (regexp_replace(btrim(lower((formalname)::text)), '[^а-яА-Яa-zA-Z0-9-]{1,}'::text, '-'::text, 'g'::text) = 'москва'::text))

-> Bitmap Heap Scan on addrobj_77 addrobj (cost=18.45..540.77 rows=3 width=115)
Recheck Cond: (aolevel = ANY ('{1,4,6}'::bigint[]))

Filter: ((actstatus = 1) AND ((regioncode)::text = '77'::text) AND (regexp_replace(btrim(lower((formalname)::text)), '[^а-яА-Яa-zA-Z0-9-]{1,}'::text, '-'::text, 'g'::text) = 'москва'::text))

-> Bitmap Index Scan on addrobj_77_aolevel_index (cost=0.00..18.44 rows=759 width=0)
Index Cond: (aolevel = ANY ('{1,4,6}'::bigint[]))

$dbh2->query('SET constraint_exclusion = on');
$q = $dbh2->prepare("SELECT 
  o0_.aoid AS aoid0, 
  o0_.aoguid AS aoguid1, 
  o0_.formalnamepath AS formalnamepath2, 
  o0_.regioncode AS regioncode3, 
  o0_.aolevel AS aolevel4, 
  o0_.actstatus AS actstatus5 
FROM 
  object_name o0_ 
WHERE 
  o0_.regioncode = '77' AND o0_.formalnamepath = 'москва'");
if (!$q->execute()) {
  var_dump($q->errorInfo());
}
$stop = microtime(true);

if (!$q->execute(array('77', 'москва')) {
  var_dump($q->errorInfo());
}
$stop = microtime(true);