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, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    5696, 5621, 5892, 5719, 5706, 5720, 5703, 
    4894, 4962, 5691, 5687, 3733, 4915, 
    3589, 4976, 3811, 6093, 6194, 4935, 
    3734, 3641, 5700, 6064, 3798, 4931, 
    3730, 3638, 3729, 3851, 6204, 3942, 
    3732, 3448, 3728, 3852, 3850, 3731, 
    3642, 3943, 3623, 3645, 3637, 3950, 
    6074, 3644, 3864, 3940, 3865, 6117, 
    3869, 3948, 3941, 6068, 3951, 5812, 
    3949, 6097, 8612, 6073, 8464, 8469, 
    10025, 8724, 8445, 8811, 8441, 8446, 
    8440, 8593, 8595, 8444, 8471, 8594, 
    8457, 8828, 8466, 8831, 8276, 8365, 
    8585
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00219

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "56.65"
    },
    "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": 80,
      "rows_produced_per_join": 80,
      "filtered": "100.00",
      "index_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`product_id` in (5696,5621,5892,5719,5706,5720,5703,4894,4962,5691,5687,3733,4915,3589,4976,3811,6093,6194,4935,3734,3641,5700,6064,3798,4931,3730,3638,3729,3851,6204,3942,3732,3448,3728,3852,3850,3731,3642,3943,3623,3645,3637,3950,6074,3644,3864,3940,3865,6117,3869,3948,3941,6068,3951,5812,3949,6097,8612,6073,8464,8469,10025,8724,8445,8811,8441,8446,8440,8593,8595,8444,8471,8594,8457,8828,8466,8831,8276,8365,8585)) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "48.65",
        "eval_cost": "8.00",
        "prefix_cost": "56.65",
        "data_read_per_join": "365K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "unit_name"
      ]
    }
  }
}