SELECT 
  cscart_product_prices.product_id, 
  MIN(
    IF(
      cscart_product_prices.percentage_discount = 0, 
      cscart_product_prices.price, 
      cscart_product_prices.price - (
        cscart_product_prices.price * cscart_product_prices.percentage_discount
      )/ 100
    )
  ) AS price 
FROM 
  cscart_product_prices 
WHERE 
  cscart_product_prices.product_id IN (
    1230, 1227, 77, 1235, 1958, 1712, 1759, 
    1002, 1381, 1320, 359, 1892, 1176, 1201, 
    1191, 1182, 1825, 1824, 1821, 1761, 
    1823, 1822, 1193, 701
  ) 
  AND cscart_product_prices.lower_limit = 1 
  AND cscart_product_prices.usergroup_id IN (0, 1) 
GROUP BY 
  cscart_product_prices.product_id

Query time 0.00121

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_prices",
      "access_type": "range",
      "possible_keys": ["usergroup", "product_id", "lower_limit", "usergroup_id"],
      "key": "product_id",
      "key_length": "3",
      "used_key_parts": ["product_id"],
      "rows": 26,
      "filtered": 6.836732864,
      "index_condition": "cscart_product_prices.product_id in (1230,1227,77,1235,1958,1712,1759,1002,1381,1320,359,1892,1176,1201,1191,1182,1825,1824,1821,1761,1823,1822,1193,701)",
      "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}