SELECT 
  * 
FROM 
  cscart_product_options_exceptions 
WHERE 
  product_id = 9821 
ORDER BY 
  exception_id

Query time 0.00024

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_options_exceptions ref product product 3 const 1 Using where; Using filesort

Result

exception_id product_id combination
3006 9821 a:2:{i:883;s:5:"17846";i:884;s:2:"-1";}