optimizing a select query of 1.5 million entry
Would that work?

SELECT s0_.id, s0_.lowresimageurl
FROM app_instagram_shop_picture s0_
FORCE INDEX ( idx_deleted_shopId )
WHERE EXISTS (SELECT 1 FROM app_instagram_shop s1_
            WHERE s0_.shop_id = s1_.id
                AND s1_.deletedAt IS NULL
                AND s1_.expirydate IS NULL
                AND s0_.deletedAt IS NULL)
ORDER BY s0_.checked ASC
LIMIT 0 , 30