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 (
    5623, 5624, 5625, 5626, 5627, 5628, 5629, 
    5630, 5631, 5632, 5633, 5634, 5635, 
    5636, 5637, 5638, 5639, 5640, 5641, 
    5642, 5643, 5644, 5645, 5646, 5647, 
    5648, 5649, 5650, 5651, 5652, 5653, 
    5654, 5655, 5656, 5657, 5658, 5659, 
    5660, 5661, 5662, 5663, 5664, 5665, 
    5666, 5667, 3137, 1473, 1474, 1475, 
    1476, 1477, 5182, 5183, 5184, 5185, 
    5186, 5187, 1461, 1462, 1463, 1464, 
    1465, 5170, 5171, 5172, 5173, 5174, 
    5175, 1878, 1879, 1880, 1881, 1882, 
    1883, 1884, 1885, 1886, 1887, 1888, 
    1889, 1890, 1891, 1892, 1893, 1894, 
    1895, 1896, 1897, 1898, 1899, 1900, 
    1901, 1902, 1903, 1904, 1905
  ) 
  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 0.00166

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": "19.99",
        "index_condition": "(`test2_gaseus`.`cscart_product_prices`.`product_id` in (5623,5624,5625,5626,5627,5628,5629,5630,5631,5632,5633,5634,5635,5636,5637,5638,5639,5640,5641,5642,5643,5644,5645,5646,5647,5648,5649,5650,5651,5652,5653,5654,5655,5656,5657,5658,5659,5660,5661,5662,5663,5664,5665,5666,5667,3137,1473,1474,1475,1476,1477,5182,5183,5184,5185,5186,5187,1461,1462,1463,1464,1465,5170,5171,5172,5173,5174,5175,1878,1879,1880,1881,1882,1883,1884,1885,1886,1887,1888,1889,1890,1891,1892,1893,1894,1895,1896,1897,1898,1899,1900,1901,1902,1903,1904,1905))",
        "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": "((`test2_gaseus`.`cscart_product_prices`.`lower_limit` = 1) and (`test2_gaseus`.`cscart_product_prices`.`usergroup_id` in (0,1)))"
      }
    }
  }
}