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 (
    430866, 430910, 431046, 431131, 431291, 
    381713, 339691, 430896, 430932, 431185, 
    431220, 431333, 431501, 430631, 430653, 
    430730, 430887, 430900, 431072, 431205, 
    431345, 430885, 430999, 431338, 430634, 
    430645, 430761, 430862, 430937, 430992, 
    431054, 431140, 431316, 381711, 339733, 
    339804, 430708, 430870, 431077, 431326, 
    339600, 339781, 430677, 430738, 430994, 
    339831, 430714, 430749, 430797, 430853, 
    430865, 430881, 431365, 430947, 431024, 
    431192, 431463, 430802, 430873, 430936, 
    431242, 430656, 430993, 431395, 431429, 
    339488, 430846, 430960, 431019, 431039, 
    431061, 430626, 430707, 430836, 430969, 
    431003, 431011, 431052, 431322, 430652, 
    430704, 430841, 430905, 430984, 431091, 
    431248, 431315, 430810, 431051, 431113, 
    431503, 430837, 430861, 431074, 431200, 
    431247, 431439, 431178, 431252, 431487
  ) 
  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 0.00198

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 (430866,430910,431046,431131,431291,381713,339691,430896,430932,431185,431220,431333,431501,430631,430653,430730,430887,430900,431072,431205,431345,430885,430999,431338,430634,430645,430761,430862,430937,430992,431054,431140,431316,381711,339733,339804,430708,430870,431077,431326,339600,339781,430677,430738,430994,339831,430714,430749,430797,430853,430865,430881,431365,430947,431024,431192,431463,430802,430873,430936,431242,430656,430993,431395,431429,339488,430846,430960,431019,431039,431061,430626,430707,430836,430969,431003,431011,431052,431322,430652,430704,430841,430905,430984,431091,431248,431315,430810,431051,431113,431503,430837,430861,431074,431200,431247,431439,431178,431252,431487)) and (`webmarco`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}