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 (
    200, 201, 202, 271, 272, 273, 274, 275, 
    276, 277, 325, 326, 327, 328, 329, 330, 
    415, 416, 417, 418, 3616, 3617, 3618, 
    4080, 4081, 4082, 4083, 4084, 4085, 
    4086, 4156, 4157, 4158, 4159, 4160, 
    4161, 4162, 4209, 4210, 4211, 4212, 
    4213, 4214, 4215, 3102, 3110, 6670, 
    6685, 6698, 3095, 3101, 3108, 6683, 
    6697, 3099, 19, 20, 21, 3929, 3930, 3931, 
    3411, 3415, 3417, 6942, 3410, 3413, 
    3416, 6940, 3414, 6938, 6941, 6944, 
    3412, 6937, 6939, 6943, 6724, 3100, 
    3106, 3114, 3120, 3125, 3153, 3154, 
    6672, 6688, 6689, 6694, 6702, 6706, 
    6708, 6726, 6725, 3103, 3097
  ) 
  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 0.00216

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "67.21"
    },
    "grouping_operation": {
      "using_filesort": false,
      "table": {
        "table_name": "cscart_product_prices",
        "access_type": "range",
        "possible_keys": [
          "usergroup",
          "product_id",
          "lower_limit",
          "usergroup_id"
        ],
        "key": "product_id",
        "used_key_parts": [
          "product_id"
        ],
        "key_length": "3",
        "rows_examined_per_scan": 96,
        "rows_produced_per_join": 19,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (200,201,202,271,272,273,274,275,276,277,325,326,327,328,329,330,415,416,417,418,3616,3617,3618,4080,4081,4082,4083,4084,4085,4086,4156,4157,4158,4159,4160,4161,4162,4209,4210,4211,4212,4213,4214,4215,3102,3110,6670,6685,6698,3095,3101,3108,6683,6697,3099,19,20,21,3929,3930,3931,3411,3415,3417,6942,3410,3413,3416,6940,3414,6938,6941,6944,3412,6937,6939,6943,6724,3100,3106,3114,3120,3125,3153,3154,6672,6688,6689,6694,6702,6706,6708,6726,6725,3103,3097))",
        "cost_info": {
          "read_cost": "65.29",
          "eval_cost": "1.92",
          "prefix_cost": "67.21",
          "data_read_per_join": "460"
        },
        "used_columns": [
          "product_id",
          "price",
          "percentage_discount",
          "lower_limit",
          "usergroup_id"
        ],
        "attached_condition": "((`gaseus`.`cscart_product_prices`.`lower_limit` = 1) and (`gaseus`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}

Result

product_id price
19 0.00000000
20 0.00000000
21 0.00000000
200 0.00000000
201 0.00000000
202 0.00000000
271 0.00000000
272 0.00000000
273 0.00000000
274 0.00000000
275 0.00000000
276 0.00000000
277 0.00000000
325 0.00000000
326 0.00000000
327 0.00000000
328 0.00000000
329 0.00000000
330 0.00000000
415 0.00000000
416 0.00000000
417 0.00000000
418 0.00000000
3095 709.00000000
3097 336.00000000
3099 535.00000000
3100 0.00000000
3101 632.00000000
3102 618.00000000
3103 621.00000000
3106 0.00000000
3108 632.00000000
3110 618.00000000
3114 0.00000000
3120 0.00000000
3125 0.00000000
3153 0.00000000
3154 0.00000000
3410 688.00000000
3411 535.00000000
3412 702.00000000
3413 688.00000000
3414 550.00000000
3415 535.00000000
3416 688.00000000
3417 535.00000000
3616 0.00000000
3617 0.00000000
3618 0.00000000
3929 0.00000000
3930 0.00000000
3931 0.00000000
4080 0.00000000
4081 0.00000000
4082 0.00000000
4083 0.00000000
4084 0.00000000
4085 0.00000000
4086 0.00000000
4156 0.00000000
4157 0.00000000
4158 0.00000000
4159 0.00000000
4160 0.00000000
4161 0.00000000
4162 0.00000000
4209 0.00000000
4210 0.00000000
4211 0.00000000
4212 0.00000000
4213 0.00000000
4214 0.00000000
4215 0.00000000
6670 696.00000000
6672 0.00000000
6683 632.00000000
6685 618.00000000
6688 0.00000000
6689 0.00000000
6694 0.00000000
6697 632.00000000
6698 618.00000000
6702 0.00000000
6706 0.00000000
6708 0.00000000
6724 0.00000000
6725 0.00000000
6726 0.00000000
6937 702.00000000
6938 550.00000000
6939 702.00000000
6940 688.00000000
6941 550.00000000
6942 535.00000000
6943 702.00000000
6944 550.00000000