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 (
    59410, 64688, 60890, 61485, 60138, 62054, 
    62226, 61077, 61075, 59420, 61211, 
    61517, 61693, 59650, 61692, 61071, 
    61344, 61520, 61074, 61516, 62060, 
    64821, 62434, 63345
  ) 
  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 0.00084

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 (59410,64688,60890,61485,60138,62054,62226,61077,61075,59420,61211,61517,61693,59650,61692,61071,61344,61520,61074,61516,62060,64821,62434,63345) and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result

product_id price
59410 324.000000
59420 156.000000
59650 182.000000
60138 230.000000
60890 330.000000
61071 340.000000
61074 395.000000
61075 395.000000
61077 425.000000
61211 202.000000
61344 330.000000
61485 220.000000
61516 185.000000
61517 270.000000
61520 228.000000
61692 260.000000
61693 260.000000
62054 245.000000
62060 290.000000
62226 249.000000
62434 364.000000
63345 229.000000
64688 290.000000
64821 280.000000