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 (
    62862, 62365, 62658, 62428, 64363, 62412, 
    62420, 65530, 65443, 65429, 65430, 
    65446, 65440, 65449, 65480, 65444, 
    65471, 65427, 65431, 65437, 65447, 
    65470, 65442, 65445
  ) 
  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 0.00089

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": "9",
      "used_key_parts": ["product_id", "usergroup_id", "lower_limit"],
      "rowid_filter": {
        "range": {
          "key": "lower_limit",
          "used_key_parts": ["lower_limit", "product_id", "usergroup_id"]
        },
        "rows": 48,
        "selectivity_pct": 1.779095626
      },
      "rows": 48,
      "filtered": 100,
      "index_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.product_id in (62862,62365,62658,62428,64363,62412,62420,65530,65443,65429,65430,65446,65440,65449,65480,65444,65471,65427,65431,65437,65447,65470,65442,65445) and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result