SELECT 
  cscart_product_descriptions.product_id, 
  cscart_product_descriptions.short_description, 
  IF(
    cscart_product_descriptions.short_description = '' 
    OR cscart_product_descriptions.short_description IS NULL, 
    cscart_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    91978, 91981, 82563, 82567, 82571, 91977, 
    91979, 91980, 91982, 91983, 82556, 
    91970, 91973, 91985, 91986, 91987, 
    91988, 91989, 91990, 91991, 91969, 
    91971, 91972, 91974, 91975, 82557, 
    82369, 82560, 82565, 82569, 82573, 
    82562, 82566, 82570, 91968, 82555, 
    82553, 82554, 82559, 82552, 82564, 
    82568, 82572, 91976, 91984, 82558, 
    92593, 92594, 92595, 92596, 94707, 
    94708, 96739, 96985, 96986, 96987, 
    96988, 96989, 96990, 96991, 96992, 
    96993, 96994, 96995, 96996, 96997, 
    96999, 97000, 97001, 97002, 97003, 
    97004, 97005, 97006, 97007, 97008, 
    97009, 97010, 97831, 97832, 98290, 
    98291, 98292, 98293, 98294, 98295, 
    98296, 98297, 98298, 98299, 98300, 
    98301, 98302, 98303, 98304, 98305
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00178

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "43.24"
    },
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": [
        "PRIMARY",
        "product_id"
      ],
      "key": "PRIMARY",
      "used_key_parts": [
        "product_id",
        "lang_code"
      ],
      "key_length": "9",
      "rows_examined_per_scan": 96,
      "rows_produced_per_join": 96,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "33.64",
        "eval_cost": "9.60",
        "prefix_cost": "43.24",
        "data_read_per_join": "366K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (91978,91981,82563,82567,82571,91977,91979,91980,91982,91983,82556,91970,91973,91985,91986,91987,91988,91989,91990,91991,91969,91971,91972,91974,91975,82557,82369,82560,82565,82569,82573,82562,82566,82570,91968,82555,82553,82554,82559,82552,82564,82568,82572,91976,91984,82558,92593,92594,92595,92596,94707,94708,96739,96985,96986,96987,96988,96989,96990,96991,96992,96993,96994,96995,96996,96997,96999,97000,97001,97002,97003,97004,97005,97006,97007,97008,97009,97010,97831,97832,98290,98291,98292,98293,98294,98295,98296,98297,98298,98299,98300,98301,98302,98303,98304,98305)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}