SELECT 
  * 
FROM 
  cscart_product_options_inventory 
WHERE 
  product_id = 627 
  AND combination_hash = '2969293540'

Query time 0.00023

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_product_options_inventory const PRIMARY,pc PRIMARY 4 const 1

Result

product_id product_code combination_hash combination amount temp position price weight min_qty max_qty qty_step list_qty_count aval_status
627 MDM-KD-L04-8004 2969293540 658_15505_1218_22769 0.00 N 0 36.10 8.00 0 0 0 0 100