Как найти метод с медленным запросом к БД и как сократить время выполнения?

SEL ECT
   COUNT(DISTINCT
         BE.ID) as C
FR OM
   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
WHERE 1 = 1
   AND ((
         EXISTS (
            SEL ECT
               IBLOCK_ID
            FR OM
               b_iblock_site
            WHERE
               IBLOCK_ID = B.ID
               AND (SITE_ID = 's1') ) )
      AND ( (
            BE.ACTIVE_TO >= now()
            OR BE.ACTIVE_TO IS NULL )
         AND (BE.ACTIVE_FROM <= now()
            OR BE.ACTIVE_FROM IS NULL ) )
   AND (BE.ACTIVE = 'Y')
      AND (BE.IBLOCK_ID = '2'))
   AND (BE.WF_STATUS_ID = 1
      AND BE.WF_PARENT_ELEMENT_ID IS NULL )
   AND ( B.ID IN (
         SELECT IBLOCK_ID
         FR OM b_iblock_group IBG
         WH ERE IBG.GROUP_ID IN (2)
            AND IBG.PERMISSION >= 'R'
            AND (
               IBG.PERMISSION = 'X'
               OR B.ACTIVE = 'Y'
            ))
      OR (
         B.RIGHTS_MODE = 'E'
         AND EXISTS (
            SELECT
               ER.ELEMENT_ID
            FR OM
               b_iblock_element_right ER
               INNER JOIN b_iblock_right IBR ON
                  IBR.ID = ER.RIGHT_ID
               INNER JOIN b_user_access UA ON
                  UA.ACCESS_CODE = IBR.GROUP_CODE
                  AND UA.USER_ID = 0
            WH ERE
               ER.ELEMENT_ID = BE.ID
               AND IBR.OP_EREAD = 'Y'
         ) )
)