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 (
    69928, 69929, 69930, 70104, 70103, 70102, 
    71581, 71579, 71580, 72169, 72168, 
    72909, 72910, 74006, 74007, 81610, 
    81619, 81620, 81611, 81612, 81613, 
    81614, 81615, 81616, 81617, 81601, 
    81602, 81603, 81604, 81605, 81606, 
    81607, 81608, 81609, 82683, 82682, 
    82681, 83187, 83188, 83189, 83190, 
    83191, 84471, 84472, 85931, 85932, 
    86197, 86189, 86196, 86195, 86194, 
    86193, 86192, 86191, 86190, 86188, 
    86287, 86286, 86285, 86706, 86711, 
    86712, 86713, 86714, 86715, 86707, 
    86708, 86709, 86710
  )

Query time 0.01451

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": 69,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (69928,69929,69930,70104,70103,70102,71581,71579,71580,72169,72168,72909,72910,74006,74007,81610,81619,81620,81611,81612,81613,81614,81615,81616,81617,81601,81602,81603,81604,81605,81606,81607,81608,81609,82683,82682,82681,83187,83188,83189,83190,83191,84471,84472,85931,85932,86197,86189,86196,86195,86194,86193,86192,86191,86190,86188,86287,86286,86285,86706,86711,86712,86713,86714,86715,86707,86708,86709,86710)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}