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 (
    72988, 72987, 72986, 72985, 72984, 72983, 
    72982, 72981, 72980, 72989, 73000, 
    73001, 73005, 73004, 73003, 73002, 
    73006, 74650, 74649, 74651, 74657, 
    74656, 74655, 74654, 74653, 74652, 
    74688, 74687
  )

Query time 0.00318

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": 28,
          "filtered": 100,
          "index_condition": "pfv.variant_id in (72988,72987,72986,72985,72984,72983,72982,72981,72980,72989,73000,73001,73005,73004,73003,73002,73006,74650,74649,74651,74657,74656,74655,74654,74653,74652,74688,74687)"
        }
      },
      {
        "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'"
        }
      }
    ]
  }
}