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 (
    84803, 91082, 82718, 82719, 83456, 83457, 
    89764, 83073, 83626, 90909, 90988, 
    85083, 85169, 85215, 85261, 86178, 
    86201, 86502, 86778, 82633, 82634, 
    83530, 83531, 85316, 85413, 85464, 
    85515, 86470, 86746, 86973, 87034, 
    89074, 89820, 89872, 89944, 91510, 
    82851, 82862, 82924, 82935, 82997, 
    83008, 83444, 83449, 83513, 83521, 
    85123, 84329, 84330, 86195, 86218, 
    86527, 86803, 89079, 89080, 82716, 
    83454, 85362, 86609, 86610, 86678, 
    86679, 83559, 83560, 83561, 83562, 
    89770, 89771, 84814, 84815, 84832, 
    84833, 84844, 84845, 91137, 91223, 
    91278, 85320, 85321, 85417, 85418, 
    85468, 85469, 85519, 85520, 86184, 
    86185, 86207, 86208, 86508, 86509, 
    86784, 86785, 83053, 83055, 83602
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00179

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 (84803,91082,82718,82719,83456,83457,89764,83073,83626,90909,90988,85083,85169,85215,85261,86178,86201,86502,86778,82633,82634,83530,83531,85316,85413,85464,85515,86470,86746,86973,87034,89074,89820,89872,89944,91510,82851,82862,82924,82935,82997,83008,83444,83449,83513,83521,85123,84329,84330,86195,86218,86527,86803,89079,89080,82716,83454,85362,86609,86610,86678,86679,83559,83560,83561,83562,89770,89771,84814,84815,84832,84833,84844,84845,91137,91223,91278,85320,85321,85417,85418,85468,85469,85519,85520,86184,86185,86207,86208,86508,86509,86784,86785,83053,83055,83602)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}