SELECT 
  min_qty, 
  max_qty, 
  qty_step 
FROM 
  cscart_product_options_inventory 
WHERE 
  combination_hash = 435738575

Query time 0.00019

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
1 0 17.28