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 (
    61081, 62246, 60906, 62040, 61425, 62167, 
    62023, 64273, 30013, 61697, 60484, 
    30012
  ) 
  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 0.00081

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": 24,
        "selectivity_pct": 0.889547813
      },
      "rows": 24,
      "filtered": 100,
      "index_condition": "cscart_product_prices.lower_limit = 1 and cscart_product_prices.product_id in (61081,62246,60906,62040,61425,62167,62023,64273,30013,61697,60484,30012) and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result

product_id price
30012 180.000000
30013 190.000000
60484 285.000000
60906 265.000000
61081 375.000000
61425 310.000000
61697 285.000000
62023 330.000000
62040 458.000000
62167 375.000000
62246 335.000000
64273 370.000000