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 (
    430994, 430999, 431345, 430634, 430645, 
    430714, 430862, 430885, 430887, 430992, 
    431338, 430656, 430738, 430761, 430865, 
    431054, 431316, 430626, 430870, 431192, 
    430708, 430797, 430853, 431019, 431326, 
    431365, 430677, 430749, 431061, 430802, 
    430846, 430873, 430881, 431011, 431024, 
    431242, 430960, 430993, 431039, 431322, 
    430836, 430936, 431003, 431052, 431395, 
    431429, 430704, 430707, 430905, 430841, 
    430969, 431020, 431022, 431091, 431248, 
    431264, 430810, 431051, 431315, 431503, 
    430652, 430861, 430940, 430984, 431113, 
    431178, 431193, 431247, 431487, 431006, 
    431200, 431301, 431426, 431439, 435509, 
    430782, 430837, 431074, 431339, 430816, 
    430926, 431252, 430641, 430794, 430968, 
    431275, 430788, 430879, 431171, 431334, 
    430661, 430811, 431098, 431055, 430742, 
    430839, 430675, 430800, 430805, 430855
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00225

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "140.18"
    },
    "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": 100,
      "rows_produced_per_join": 100,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "120.18",
        "eval_cost": "20.00",
        "prefix_cost": "140.18",
        "data_read_per_join": "682K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`webmarco`.`cscart_product_descriptions`.`product_id` in (430994,430999,431345,430634,430645,430714,430862,430885,430887,430992,431338,430656,430738,430761,430865,431054,431316,430626,430870,431192,430708,430797,430853,431019,431326,431365,430677,430749,431061,430802,430846,430873,430881,431011,431024,431242,430960,430993,431039,431322,430836,430936,431003,431052,431395,431429,430704,430707,430905,430841,430969,431020,431022,431091,431248,431264,430810,431051,431315,431503,430652,430861,430940,430984,431113,431178,431193,431247,431487,431006,431200,431301,431426,431439,435509,430782,430837,431074,431339,430816,430926,431252,430641,430794,430968,431275,430788,430879,431171,431334,430661,430811,431098,431055,430742,430839,430675,430800,430805,430855)) and (`webmarco`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}