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 (
    430726, 431012, 431056, 431186, 430793, 
    430799, 431392, 430683, 431034, 431301, 
    431354, 431504, 430877, 430879, 431166, 
    431289, 431334, 430926, 430946, 431344, 
    430659, 430920, 430997, 431000, 431020, 
    431218, 431244, 431406, 430706, 430741, 
    430864, 431021, 431291, 431309, 431322, 
    431368, 431487, 430792, 430858, 430882, 
    431248, 431252, 431280, 339481, 430761, 
    430830, 431230, 431349, 431429, 431469, 
    430919, 430949, 430975, 431038, 431101, 
    431295, 431303, 431360, 431376, 431420, 
    431464, 430642, 430740, 431410, 431424, 
    430671, 431470, 430739, 430867, 430957, 
    431047, 431055, 431060, 431279, 431474, 
    430643, 430679, 431211, 431341, 431350, 
    430735, 430814, 430948, 431237, 392168, 
    431246, 430734, 430764, 430798, 431234, 
    431287, 430934, 430982, 431010, 431149, 
    431273, 431324, 430667, 430718, 430754
  ) 
  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 0.00149

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "280.31"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "usergroup",
        "used_key_parts": [
          "product_id",
          "usergroup_id",
          "lower_limit"
        ],
        "key_length": "9",
        "rows_examined_per_scan": 200,
        "rows_produced_per_join": 200,
        "filtered": "100.00",
        "cost_info": {
          "read_cost": "240.31",
          "eval_cost": "40.00",
          "prefix_cost": "280.31",
          "data_read_per_join": "12K"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`webmarco`.`cscart_product_prices`.`lower_limit` = 1) and (`webmarco`.`cscart_product_prices`.`product_id` in (430726,431012,431056,431186,430793,430799,431392,430683,431034,431301,431354,431504,430877,430879,431166,431289,431334,430926,430946,431344,430659,430920,430997,431000,431020,431218,431244,431406,430706,430741,430864,431021,431291,431309,431322,431368,431487,430792,430858,430882,431248,431252,431280,339481,430761,430830,431230,431349,431429,431469,430919,430949,430975,431038,431101,431295,431303,431360,431376,431420,431464,430642,430740,431410,431424,430671,431470,430739,430867,430957,431047,431055,431060,431279,431474,430643,430679,431211,431341,431350,430735,430814,430948,431237,392168,431246,430734,430764,430798,431234,431287,430934,430982,431010,431149,431273,431324,430667,430718,430754)) and (`webmarco`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}