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 (
    2772, 2773, 2774, 2775, 2776, 2777, 2845, 
    2846, 2847, 2848, 2849, 2850, 2851, 
    2852, 2853, 2854, 2855, 2856, 2857, 
    2858, 2859, 2860, 2861, 2862, 2942, 
    2943, 2944, 2945, 2946, 2947, 2948, 
    2949, 2950, 3037, 3038, 3039, 3040, 
    3041, 3042, 3043, 3044, 3045, 3853, 
    5790, 5791, 5792, 5793, 5794, 5795, 
    5796, 5797, 5798, 6307, 6308, 6309, 
    6310, 6311, 6357, 6358, 6359, 6360, 
    6361, 6362, 6363, 6364, 6365, 6431, 
    6432, 6433, 6434, 6435, 6436, 6437, 
    6438, 6439, 6440, 6441, 6442, 6443, 
    6444, 6445, 6446, 6447, 6526, 6527, 
    6528, 6529, 6530, 6531, 6532, 6533, 
    6534, 6615, 6616, 6617, 6618
  ) 
  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 0.00123

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "67.66"
    },
    "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": 97,
        "rows_produced_per_join": 19,
        "filtered": "20.00",
        "index_condition": "(`gaseus`.`cscart_product_prices`.`product_id` in (2772,2773,2774,2775,2776,2777,2845,2846,2847,2848,2849,2850,2851,2852,2853,2854,2855,2856,2857,2858,2859,2860,2861,2862,2942,2943,2944,2945,2946,2947,2948,2949,2950,3037,3038,3039,3040,3041,3042,3043,3044,3045,3853,5790,5791,5792,5793,5794,5795,5796,5797,5798,6307,6308,6309,6310,6311,6357,6358,6359,6360,6361,6362,6363,6364,6365,6431,6432,6433,6434,6435,6436,6437,6438,6439,6440,6441,6442,6443,6444,6445,6446,6447,6526,6527,6528,6529,6530,6531,6532,6533,6534,6615,6616,6617,6618))",
        "cost_info": {
          "read_cost": "65.72",
          "eval_cost": "1.94",
          "prefix_cost": "67.66",
          "data_read_per_join": "465"
        },
        "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)))"
      }
    }
  }
}