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 (
    97971, 97972, 97973, 97974, 97975, 97976, 
    97977, 97978, 97979, 97980, 97981, 
    97982, 97983, 97984, 97985, 97986, 
    97987, 98001, 98040, 98041, 98042, 
    98043, 98044, 98045, 98046, 98047, 
    98048, 98049, 98050, 98051, 98084, 
    98085, 98086, 98087, 98088, 98089, 
    98090, 98091, 98092, 98093, 98094, 
    98095, 98096, 98097, 98098, 98099, 
    98100, 98101
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00113

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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": 48,
      "rows_produced_per_join": 48,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (97971,97972,97973,97974,97975,97976,97977,97978,97979,97980,97981,97982,97983,97984,97985,97986,97987,98001,98040,98041,98042,98043,98044,98045,98046,98047,98048,98049,98050,98051,98084,98085,98086,98087,98088,98089,98090,98091,98092,98093,98094,98095,98096,98097,98098,98099,98100,98101)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
97971
97972
97973
97974
97975
97976
97977
97978
97979
97980
97981
97982
97983
97984
97985
97986
97987
98001
98040
98041
98042
98043
98044
98045
98046
98047
98048
98049
98050
98051
98084
98085
98086
98087
98088
98089
98090
98091
98092
98093
98094
98095
98096
98097
98098
98099
98100
98101