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 (
    14096, 14108, 14094, 14047, 14082, 14058, 
    14107, 14081, 14115, 14114, 14113, 
    14046, 14104, 14074, 14662, 14073, 
    14072, 14099, 14098, 14071, 14133, 
    14106, 14070, 14045
  ) 
  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 0.00072

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.06190128,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_prices",
          "access_type": "range",
          "possible_keys": [
            "usergroup",
            "product_id",
            "lower_limit",
            "usergroup_id"
          ],
          "key": "usergroup",
          "key_length": "9",
          "used_key_parts": ["product_id", "usergroup_id", "lower_limit"],
          "loops": 1,
          "rows": 48,
          "cost": 0.04656984,
          "filtered": 49.95571136,
          "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.product_id in (14096,14108,14094,14047,14082,14058,14107,14081,14115,14114,14113,14046,14104,14074,14662,14073,14072,14099,14098,14071,14133,14106,14070,14045) and cscart_product_prices.usergroup_id in (0,1)"
        }
      }
    ]
  }
}