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 (
    81610, 81595, 81654, 81637, 81619, 81590, 
    81662, 81649, 81632, 81706, 81615, 
    81639, 81697, 81652, 81622, 81660, 
    81669, 81693, 81628, 81700, 81606, 
    81644, 81703, 81601, 81687, 81679, 
    81666, 81683, 139611, 81689, 81674, 
    151100, 151062
  )

Query time 0.00085

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "141.93"
    },
    "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": 33,
          "rows_produced_per_join": 33,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "39.65",
            "eval_cost": "6.60",
            "prefix_cost": "46.25",
            "data_read_per_join": "528"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ],
          "attached_condition": "(`webmarco`.`p`.`product_id` in (81610,81595,81654,81637,81619,81590,81662,81649,81632,81706,81615,81639,81697,81652,81622,81660,81669,81693,81628,81700,81606,81644,81703,81601,81687,81679,81666,81683,139611,81689,81674,151100,151062))"
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "webmarco.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 33,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "33.00",
            "eval_cost": "6.60",
            "prefix_cost": "85.85",
            "data_read_per_join": "12K"
          },
          "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": [
            "webmarco.p.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 46,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "46.74",
            "eval_cost": "9.35",
            "prefix_cost": "141.93",
            "data_read_per_join": "4K"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      }
    ]
  }
}