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 = 'vi' 
WHERE 
  pfv.variant_id IN (
    68616, 70118, 70119, 70146, 70147, 70941, 
    70940, 70942, 70944, 70943, 70945, 
    76743, 76744, 76845, 76844, 76853, 
    76851, 76852, 76855, 76854, 79215, 
    79216, 79214, 79237, 79238, 79236, 
    79245, 79246, 79247, 81687, 81688, 
    82231, 82240, 82241, 82242, 82243, 
    82244, 82245, 82246, 82247, 82248, 
    82249, 82250, 82232, 82233, 82234, 
    82235, 82236, 82237, 82238, 82239, 
    82262, 82271, 82272, 82273, 82274, 
    82275, 82276, 82277, 82278, 82279, 
    82280, 82281, 82263, 82264, 82265, 
    82266, 82267, 82268, 82269, 82270, 
    82386, 82387, 82388, 82389, 82393, 
    82392, 82391, 82390, 83212, 83213
  )

Query time 0.00606

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": 81,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (68616,70118,70119,70146,70147,70941,70940,70942,70944,70943,70945,76743,76744,76845,76844,76853,76851,76852,76855,76854,79215,79216,79214,79237,79238,79236,79245,79246,79247,81687,81688,82231,82240,82241,82242,82243,82244,82245,82246,82247,82248,82249,82250,82232,82233,82234,82235,82236,82237,82238,82239,82262,82271,82272,82273,82274,82275,82276,82277,82278,82279,82280,82281,82263,82264,82265,82266,82267,82268,82269,82270,82386,82387,82388,82389,82393,82392,82391,82390,83212,83213)"
        }
      },
      {
        "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 = 'vi'"
        }
      }
    ]
  }
}