SELECT 
  * 
FROM 
  cscart_product_options_inventory 
WHERE 
  product_id = 10066 
  AND combination_hash = '3052162787'

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
10066 ODV-KRD-100-FR 3052162787 857_17634 1.00 N 1 274.80 2.00 0 0 0 0 115