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 (
    2127, 2305, 1812, 2038, 2306, 2129, 2171, 
    2039, 2040, 1985, 2114, 2344, 1949, 
    2041, 2318, 1961, 2042, 1986, 2343, 
    2077, 2172, 2185, 2159, 2216, 2218, 
    2229, 2228, 2186, 2184, 1934, 2358, 
    1994, 2006, 2075, 1962, 2065, 1992, 
    2008, 1984, 1993, 1936, 2238, 2237, 
    2311, 2298, 2043, 1954, 1953, 1752, 
    1827, 1870, 1803, 1828, 1754, 1770, 
    1879, 1874, 1829, 1864, 1904, 1842, 
    1781, 1894, 2153, 1886, 1887, 2085, 
    2195, 2130, 2382, 2011, 1919, 1922, 
    1942, 1923, 1933, 1945, 1946, 2376, 
    1746
  )

Query time 0.00037

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "2.33"
    },
    "nested_loop": [
      {
        "table": {
          "table_name": "f",
          "access_type": "ALL",
          "possible_keys": [
            "idx_group_id"
          ],
          "rows_examined_per_scan": 2,
          "rows_produced_per_join": 2,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.52",
            "eval_cost": "0.20",
            "prefix_cost": "0.72",
            "data_read_per_join": "208"
          },
          "used_columns": [
            "feature_id",
            "purpose",
            "group_id"
          ]
        }
      },
      {
        "table": {
          "table_name": "g",
          "access_type": "eq_ref",
          "possible_keys": [
            "PRIMARY"
          ],
          "key": "PRIMARY",
          "used_key_parts": [
            "id"
          ],
          "key_length": "3",
          "ref": [
            "cscartdevel.f.group_id"
          ],
          "rows_examined_per_scan": 1,
          "rows_produced_per_join": 2,
          "filtered": "100.00",
          "cost_info": {
            "read_cost": "0.50",
            "eval_cost": "0.20",
            "prefix_cost": "1.42",
            "data_read_per_join": "800"
          },
          "used_columns": [
            "id",
            "code"
          ]
        }
      },
      {
        "table": {
          "table_name": "p",
          "access_type": "ALL",
          "possible_keys": [
            "PRIMARY",
            "idx_group_id"
          ],
          "rows_examined_per_scan": 2,
          "rows_produced_per_join": 4,
          "filtered": "100.00",
          "using_join_buffer": "hash join",
          "cost_info": {
            "read_cost": "0.51",
            "eval_cost": "0.40",
            "prefix_cost": "2.33",
            "data_read_per_join": "64"
          },
          "used_columns": [
            "product_id",
            "parent_product_id",
            "group_id"
          ],
          "attached_condition": "((`cscartdevel`.`p`.`group_id` = `cscartdevel`.`f`.`group_id`) and (`cscartdevel`.`p`.`product_id` in (2127,2305,1812,2038,2306,2129,2171,2039,2040,1985,2114,2344,1949,2041,2318,1961,2042,1986,2343,2077,2172,2185,2159,2216,2218,2229,2228,2186,2184,1934,2358,1994,2006,2075,1962,2065,1992,2008,1984,1993,1936,2238,2237,2311,2298,2043,1954,1953,1752,1827,1870,1803,1828,1754,1770,1879,1874,1829,1864,1904,1842,1781,1894,2153,1886,1887,2085,2195,2130,2382,2011,1919,1922,1942,1923,1933,1945,1946,2376,1746)))"
        }
      }
    ]
  }
}