SELECT 
  cscart_ult_product_prices.product_id, 
  MIN(
    IF(
      cscart_ult_product_prices.percentage_discount = 0, 
      cscart_ult_product_prices.price, 
      cscart_ult_product_prices.price - (
        cscart_ult_product_prices.price * cscart_ult_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_ult_product_prices 
WHERE 
  cscart_ult_product_prices.product_id IN (
    10353, 8875, 9968, 8869, 526, 10355, 
    8886, 9838, 8891, 10211, 706, 10222
  ) 
  AND cscart_ult_product_prices.lower_limit = 1 
  AND cscart_ult_product_prices.company_id = 1 
  AND cscart_ult_product_prices.usergroup_id IN (0, 0, 1) 
GROUP BY 
  cscart_ult_product_prices.product_id

Query time 0.00071

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE cscart_ult_product_prices range usergroup,product_id,company_id,lower_limit,usergroup_id usergroup 13 24 Using index condition

Result

product_id price
526 1276.000000
706 170.000000
8869 3791.000000
8875 2154.000000
8886 4310.000000
8891 2569.000000
9838 110.000000
9968 105.850000
10211 2986.000000
10222 1543.220000
10353 1460.000000
10355 1360.000000