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 (
    7401, 7394, 7462, 7420, 7400, 7441, 7035, 
    7410, 7393, 7402, 7409, 7404, 7396, 
    7395, 7403, 7405, 7034, 7399, 7407, 
    7447, 7408, 7434, 7448, 7360, 7449, 
    7458, 7421, 7424, 7433, 7425, 7436, 
    7440, 7444, 7445, 7457, 7459, 7460, 
    7428, 7442, 7461, 7463, 7426, 7432, 
    7453, 7398, 7451, 7452, 7397, 7450, 
    7454, 7455, 7456, 7358
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00124

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "37.53"
    },
    "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": 53,
      "rows_produced_per_join": 53,
      "filtered": "100.00",
      "index_condition": "((`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`product_id` in (7401,7394,7462,7420,7400,7441,7035,7410,7393,7402,7409,7404,7396,7395,7403,7405,7034,7399,7407,7447,7408,7434,7448,7360,7449,7458,7421,7424,7433,7425,7436,7440,7444,7445,7457,7459,7460,7428,7442,7461,7463,7426,7432,7453,7398,7451,7452,7397,7450,7454,7455,7456,7358)) and (`softwarepirmam_hewadelivard_cscart_4`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "32.23",
        "eval_cost": "5.30",
        "prefix_cost": "37.53",
        "data_read_per_join": "241K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "unit_name"
      ]
    }
  }
}