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 (
    410066, 449188, 448854, 440745, 428934, 
    442920, 439094, 415673, 408268, 405290, 
    432307, 446699
  ) 
  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 0.00205

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.050171963,
    "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": 24,
          "cost": 0.04252208,
          "filtered": 50,
          "attached_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.product_id in (410066,449188,448854,440745,428934,442920,439094,415673,408268,405290,432307,446699) and cscart_product_prices.usergroup_id in (0,1)"
        }
      }
    ]
  }
}

Result

product_id price
405290 1452.91000000
408268 52.60000000
410066 243.13000000
415673 546.08000000
428934 1667.83000000
432307 1992.76000000
439094 1804.33000000
440745 217.58000000
442920 1861.66000000
446699 1418.53000000
448854 1189.70000000
449188 1551.92000000