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 (
    61051, 61464, 61520, 61526, 61339, 61074, 
    61452, 59797, 61524, 61413, 61516, 
    64353
  ) 
  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 0.00086

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 (61051,61464,61520,61526,61339,61074,61452,59797,61524,61413,61516,64353) and cscart_product_prices.usergroup_id in (0,1)"
    }
  }
}

Result

product_id price
59797 307.000000
61051 359.000000
61074 395.000000
61339 365.000000
61413 438.000000
61452 850.000000
61464 850.000000
61516 185.000000
61520 228.000000
61524 388.000000
61526 396.000000
64353 375.000000