Something

SELECT sku FROM olt_tbl_skus_15330,
(SELECT block_no, COUNT(block_no) AS available 
	  FROM olt_tbl_skus_15330 
	 WHERE sku 
	  LIKE '15330/19837/15882%' 
	   AND current_allotment = 1 
  GROUP BY block_no 
  ORDER BY block_no) as block_availability
WHERE block_availability.available >= 10
  AND olt_tbl_skus_15330.block_no = block_availability.block_no
ORDER BY olt_tbl_skus_15330.sku
LIMIT 10;