SELECT 
  f.feature_id, 
  f.purpose, 
  p.product_id, 
  p.parent_product_id, 
  g.id, 
  g.code 
FROM 
  cscart_product_variation_group_features AS f 
  INNER JOIN cscart_product_variation_groups AS g ON f.group_id = g.id 
  INNER JOIN cscart_product_variation_group_products AS p ON f.group_id = p.group_id 
WHERE 
  p.product_id IN (
    6013, 6014, 6015, 6016, 6017, 6018, 6019, 
    6020, 6196, 6197, 6198, 6199, 6200, 
    6732, 2836, 2837, 2838, 2839, 2840, 
    6422, 6423, 6424, 6425, 2937, 2938, 
    2939, 2940, 2941, 6522, 6523, 6524, 
    6525, 2189, 2190, 2191, 2192, 2193, 
    2194, 2195, 2196, 2197, 2720, 2721, 
    2722, 2723, 2769, 2770, 2771, 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
  )

Query time 0.00087

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "336.01"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "p",
          "access_type": "range",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "product_id"
          ],
          "key_length": "3",
          "rows_examined_per_scan": 96,
          "rows_produced_per_join": 96,
          "filtered": "100.00",
          "index_condition": "(`test2_gaseus`.`p`.`product_id` in (6013,6014,6015,6016,6017,6018,6019,6020,6196,6197,6198,6199,6200,6732,2836,2837,2838,2839,2840,6422,6423,6424,6425,2937,2938,2939,2940,2941,6522,6523,6524,6525,2189,2190,2191,2192,2193,2194,2195,2196,2197,2720,2721,2722,2723,2769,2770,2771,2772,2773,2774,2775,2776,2777,2845,2846,2847,2848,2849,2850,2851,2852,2853,2854,2855,2856,2857,2858,2859,2860,2861,2862,2942,2943,2944,2945,2946,2947,2948,2949,2950,3037,3038,3039,3040,3041,3042,3043,3044,3045,3853,5790,5791,5792,5793,5794))",
          "cost_info": {
            "read_cost": "57.61",
            "eval_cost": "9.60",
            "prefix_cost": "67.21",
            "data_read_per_join": "1K"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "test2_gaseus.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 96,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "24.00",
            "eval_cost": "9.60",
            "prefix_cost": "100.81",
            "data_read_per_join": "37K"
          },
          "used_columns": [
            "id",
            "code"
          ]
        }
      },
      {
        "table": {
          "table_name": "f",
          "access_type": "ref",
          "possible_keys": [
            "idx_group_id"
          ],
          "key": "idx_group_id",
          "used_key_parts": [
            "group_id"
          ],
          "key_length": "3",
          "ref": [
            "test2_gaseus.p.group_id"
          ],
          "rows_examined_per_scan": 7,
          "rows_produced_per_join": 672,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "168.00",
            "eval_cost": "67.20",
            "prefix_cost": "336.01",
            "data_read_per_join": "68K"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      }
    ]
  }
}