SELECT DISTINCT sub.painting_id, sub.artist_id FROM (SELECT c.painting_id, p.user_id AS artist_id FROM Comments AS c FORCE INDEX(is_visible_2) INNER JOIN Paintings AS p ON c.painting_id=p.id WHERE c.is_visible=1 AND p.is_visible=1 AND p.is_blocked=0  AND c.is_deleted='0' AND c.is_admin_deleted='0' AND c.date_created < NOW() ORDER BY c.date_created DESC  LIMIT 3960, 10) AS sub