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 (
    92766, 92767, 92768, 92775, 92776, 92777, 
    92778, 92779, 92780, 92781, 92782, 
    92783, 92784, 92785, 92786, 92787, 
    92788, 92789, 92790, 92791, 92798, 
    92799, 92800, 92801, 92802, 92803, 
    92804, 92805, 92806, 92807, 92808, 
    92809, 92810, 92811, 92812, 92813, 
    92814, 92821, 92822, 92823, 92824, 
    92825, 92826, 92827, 92828, 92829, 
    92830, 92831
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00095

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "21.63"
    },
    "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",
      "cost_info": {
        "read_cost": "16.83",
        "eval_cost": "4.80",
        "prefix_cost": "21.63",
        "data_read_per_join": "183K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (92766,92767,92768,92775,92776,92777,92778,92779,92780,92781,92782,92783,92784,92785,92786,92787,92788,92789,92790,92791,92798,92799,92800,92801,92802,92803,92804,92805,92806,92807,92808,92809,92810,92811,92812,92813,92814,92821,92822,92823,92824,92825,92826,92827,92828,92829,92830,92831)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}