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SELECT 
  * 
FROM 
  cscart_product_options_exceptions 
WHERE 
  product_id = 9840 
ORDER BY 
  exception_id

Query time 0.00090

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	3	Using where; Using filesort

Result

exception_id	product_id	combination
4248	9840	a:4:{i:1161;s:5:"21968";i:1159;s:2:"-1";i:1155;s:2:"-1";i:1149;i:-1;}
4249	9840	a:4:{i:1161;s:5:"21969";i:1159;s:2:"-1";i:1155;s:2:"-1";i:1149;i:-1;}
4250	9840	a:4:{i:1161;s:5:"21970";i:1159;s:2:"-1";i:1155;s:2:"-1";i:1149;i:-1;}