SELECT 
  * 
FROM 
  cscart_product_options_inventory 
WHERE 
  product_id = 10073 
  AND combination_hash = '308957437'

Query time 0.00020

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
10073 201230410 308957437 635_15262 0.00 N 3 81.01 25000.00 12.48 0 12.48 0 0