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 (
    69668, 69669, 71575, 71573, 71574, 71589, 
    71588, 71587, 71586, 71585, 71590, 
    71596, 71595, 71594, 71593, 71592, 
    71591, 71597, 71601, 71600, 71599, 
    71598, 71602, 71610, 71609, 71608, 
    71607, 71606, 71605, 71604, 71603, 
    71611, 71616, 71614, 71613, 71612, 
    71615, 71621, 71619, 71618, 71617, 
    71620, 71732, 71733, 71734, 71735, 
    71736, 72988, 72987, 72986, 72985, 
    72984, 72983, 72982, 72981, 72980, 
    72989, 73005, 73004, 73003, 73002, 
    73006, 74650, 74649, 74651, 75631, 
    75629, 75630, 77117, 77112, 77113, 
    77114, 77115, 77116, 81621, 81601, 
    81609, 81608, 81607, 81606, 81605, 
    81604, 81603, 81602, 81617, 81616, 
    81615, 81614, 81613, 81612, 81611, 
    81610, 81622, 81623, 81624, 81625, 
    81872, 81879, 81880, 81873, 81877, 
    81878, 81874, 81875, 81876, 86300, 
    87462, 87461, 86301, 87464, 87463, 
    86303, 86302, 87452, 87451
  )

Query time 0.01907

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": 115,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (69668,69669,71575,71573,71574,71589,71588,71587,71586,71585,71590,71596,71595,71594,71593,71592,71591,71597,71601,71600,71599,71598,71602,71610,71609,71608,71607,71606,71605,71604,71603,71611,71616,71614,71613,71612,71615,71621,71619,71618,71617,71620,71732,71733,71734,71735,71736,72988,72987,72986,72985,72984,72983,72982,72981,72980,72989,73005,73004,73003,73002,73006,74650,74649,74651,75631,75629,75630,77117,77112,77113,77114,77115,77116,81621,81601,81609,81608,81607,81606,81605,81604,81603,81602,81617,81616,81615,81614,81613,81612,81611,81610,81622,81623,81624,81625,81872,81879,81880,81873,81877,81878,81874,81875,81876,86300,87462,87461,86301,87464,87463,86303,86302,87452,87451)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}