SELECT 
  pfv.variant_id, 
  pfv.position, 
  pfvd.variant 
FROM 
  cscart_product_feature_variants AS pfv 
  INNER JOIN cscart_product_feature_variant_descriptions AS pfvd ON pfv.variant_id = pfvd.variant_id 
  AND pfvd.lang_code = 'en' 
WHERE 
  pfv.variant_id IN (
    69754, 69753, 69752, 69751, 69755, 71079, 
    71080, 71904, 71905, 73565, 73564, 
    79288, 79287, 82516, 82525, 82526, 
    82527, 82528, 82529, 82530, 82531, 
    82532, 82533, 82517, 82518, 82519, 
    82520, 82521, 82522, 82523, 82524, 
    83410, 83419, 83411, 83416, 83417, 
    83418, 83412, 83413, 83414, 84249, 
    84251, 84252, 84253, 84254, 84255, 
    84250, 85990, 85999, 86000, 86001, 
    86002, 86003, 86004, 86005, 86006, 
    86007, 86008, 86009, 85991, 85992, 
    85993, 85994, 85995, 85996, 85997, 
    85998, 86238, 86237, 86796, 86797, 
    86798
  )

Query time 0.00817

JSON explain

{
  "query_block": {
    "select_id": 1,
    "nested_loop": [
      {
        "table": {
          "table_name": "pfv",
          "access_type": "range",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "3",
          "used_key_parts": ["variant_id"],
          "rows": 72,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (69754,69753,69752,69751,69755,71079,71080,71904,71905,73565,73564,79288,79287,82516,82525,82526,82527,82528,82529,82530,82531,82532,82533,82517,82518,82519,82520,82521,82522,82523,82524,83410,83419,83411,83416,83417,83418,83412,83413,83414,84249,84251,84252,84253,84254,84255,84250,85990,85999,86000,86001,86002,86003,86004,86005,86006,86007,86008,86009,85991,85992,85993,85994,85995,85996,85997,85998,86238,86237,86796,86797,86798)"
        }
      },
      {
        "table": {
          "table_name": "pfvd",
          "access_type": "eq_ref",
          "possible_keys": ["PRIMARY"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["variant_id", "lang_code"],
          "ref": ["dev_db.pfv.variant_id", "const"],
          "rows": 1,
          "filtered": 100,
          "index_condition": "pfvd.lang_code = 'en'"
        }
      }
    ]
  }
}