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 (
    68747, 68746, 68745, 68744, 68743, 68748, 
    71192, 71191, 71190, 71189, 71193, 
    71444, 71445, 71553, 71552, 71674, 
    71675, 71676, 71677, 72194, 72193, 
    73305, 73304, 73332, 73331, 73333, 
    73417, 73418, 73416, 73519, 73518, 
    74263, 74262, 74261, 74264, 74501, 
    74502, 74500, 74504, 74505, 74503, 
    75276, 75277, 78619, 78618, 78620, 
    79008, 79230, 79231, 79229, 87216, 
    80108, 80109, 87215, 87214, 82553, 
    82552, 83067, 83068, 83205, 83206
  )

Query time 0.01683

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": 61,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (68747,68746,68745,68744,68743,68748,71192,71191,71190,71189,71193,71444,71445,71553,71552,71674,71675,71676,71677,72194,72193,73305,73304,73332,73331,73333,73417,73418,73416,73519,73518,74263,74262,74261,74264,74501,74502,74500,74504,74505,74503,75276,75277,78619,78618,78620,79008,79230,79231,79229,87216,80108,80109,87215,87214,82553,82552,83067,83068,83205,83206)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}