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 (
    58884, 62123, 29986, 60914, 29983, 29992, 
    29989, 63034, 62012, 61430, 62240, 
    63755, 62259, 61340, 61337, 62252, 
    61336, 62253, 62254, 62260, 64941, 
    62258, 64942, 64943
  ) 
  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 0.00107

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 (58884,62123,29986,60914,29983,29992,29989,63034,62012,61430,62240,63755,62259,61340,61337,62252,61336,62253,62254,62260,64941,62258,64942,64943) and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result

product_id price
29983 21.000000
29986 47.000000
29989 43.000000
29992 64.000000
58884 54.000000
60914 72.000000
61336 90.000000
61337 39.000000
61340 68.000000
61430 413.000000
62012 107.000000
62123 63.000000
62240 22.000000
62252 54.000000
62253 61.000000
62254 61.000000
62258 83.000000
62259 77.000000
62260 83.000000
63034 43.000000
63755 105.000000
64941 83.000000
64942 94.000000
64943 105.000000