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 (
    430799, 430920, 430946, 431055, 431234, 
    431354, 430671, 430739, 430786, 431252, 
    431424, 431470, 430679, 431350, 431368, 
    430755, 430793, 431349, 431186, 431246, 
    430683, 430858, 430877, 431038, 431406, 
    430740, 431411, 430667, 430882, 430961, 
    430867, 430975, 431149, 431309, 431360, 
    430659, 430764, 430948, 431010, 431410, 
    431457, 431494, 430642, 430762, 431340, 
    431343, 431376, 431045, 431211, 431230, 
    431405, 431497, 430792, 431166, 431182, 
    431274, 431284, 430711, 431341, 431505, 
    430735, 430974, 431047, 431087, 431279, 
    431403, 431495, 430830, 431152, 431287, 
    431290, 431303, 431381, 430643, 430814, 
    430919, 430965, 431025, 431231, 431465, 
    431474, 430686, 430734, 430957, 431324, 
    430718, 430934, 431425, 430754, 430798, 
    431004, 431071, 431329, 431434, 431015, 
    431240, 431260, 431355, 430765, 431060
  ) 
  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 0.00175

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 (430799,430920,430946,431055,431234,431354,430671,430739,430786,431252,431424,431470,430679,431350,431368,430755,430793,431349,431186,431246,430683,430858,430877,431038,431406,430740,431411,430667,430882,430961,430867,430975,431149,431309,431360,430659,430764,430948,431010,431410,431457,431494,430642,430762,431340,431343,431376,431045,431211,431230,431405,431497,430792,431166,431182,431274,431284,430711,431341,431505,430735,430974,431047,431087,431279,431403,431495,430830,431152,431287,431290,431303,431381,430643,430814,430919,430965,431025,431231,431465,431474,430686,430734,430957,431324,430718,430934,431425,430754,430798,431004,431071,431329,431434,431015,431240,431260,431355,430765,431060)) and (`webmarco`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}