SELECT 
  * 
FROM 
  cscart_product_options_inventory 
WHERE 
  product_id = 8878 
  AND combination_hash = '3206501316'

Query time 0.00022

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
8878 ODV-GLU-CK02-0051 3206501316 1125_21318 41.00 N 0 1286.18 22.50 0 0 0 0 1