SELECT 
  * 
FROM 
  cscart_product_options_inventory 
WHERE 
  product_id = 10141 
  AND combination_hash = '2794166752'

Query time 0.00028

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
10141 ODV-GXL-FK06-3066 2794166752 1137_21563 0.00 N 0 3887.80 38.50 0 0 0 0 2