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 (
    1909, 1136, 1135, 1134, 1133, 1132, 1131, 
    1130, 1129, 1128, 1127, 1126, 1125, 
    1124, 1123, 1111, 1110, 1109, 1108, 
    1107, 1102, 1101, 1099, 1096, 1094, 
    1092, 1088, 1054, 1053, 1051, 1050, 
    1049, 1048, 967, 966, 965, 964, 963, 
    962, 960, 959, 958, 957, 956, 955, 954, 
    953, 952
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00067

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "33.61"
    },
    "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",
      "index_condition": "((`wearethehelpful_scalesta_net`.`cscart_product_descriptions`.`product_id` in (1909,1136,1135,1134,1133,1132,1131,1130,1129,1128,1127,1126,1125,1124,1123,1111,1110,1109,1108,1107,1102,1101,1099,1096,1094,1092,1088,1054,1053,1051,1050,1049,1048,967,966,965,964,963,962,960,959,958,957,956,955,954,953,952)) and (`wearethehelpful_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "28.81",
        "eval_cost": "4.80",
        "prefix_cost": "33.61",
        "data_read_per_join": "219K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "unit_name"
      ]
    }
  }
}