SELECT 
  min_qty, 
  max_qty, 
  qty_step, 
  list_qty_count 
FROM 
  cscart_product_options_inventory 
WHERE 
  combination_hash = '1512413142'

Query time 0.00018

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

Result

min_qty max_qty qty_step list_qty_count
0 0 0 0