SELECT 
  * 
FROM 
  cscart_product_options_exceptions 
WHERE 
  product_id = 516 
ORDER BY 
  exception_id

Query time 0.00035

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 4 Using where; Using filesort

Result

exception_id product_id combination
2783 516 a:2:{i:906;s:5:"18130";i:864;s:5:"17725";}
2784 516 a:2:{i:906;s:5:"18130";i:864;s:5:"17726";}
2785 516 a:2:{i:906;s:5:"18130";i:864;s:5:"17727";}
2786 516 a:2:{i:906;s:5:"18130";i:864;s:5:"17728";}