Вот такой пример:
SELECT * FROM ( # начало подзапроса
SELECT us.user_id, us.seller_profile, us.customer_profile, us.seller_about, us.customer_about,
SUM(if(ur.etype = 1, 1, 0)) AS seller_recalls_count,
SUM(if(ur.etype = 3 OR ur.exch_type = 4, 1, 0)) AS customer_recalls_count
FROM user_settings us LEFT JOIN user_recall ur ON us.user_id = ur.recipient_id
WHERE (noindex = 0) GROUP BY us.user_id ORDER BY user_id LIMIT 5000 , 500
) as sub_table #конец подзапроса
WHERE (customer_recalls_count > 0)
OR (seller_recalls_count > 0)
OR (seller_about IS NOT NULL AND seller_about <> '')
OR (customer_about IS NOT NULL AND customer_about <> '');