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 (
    95165, 95166, 95167, 95168, 95169, 95170, 
    95171, 95172, 95173, 95174, 95175, 
    95176, 95177, 95178, 95179, 95180, 
    95181, 95182, 95183, 95184, 95185, 
    95186, 95187, 95188, 95189, 95190, 
    95191, 95192, 95193, 95194
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00078

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.52"
    },
    "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": 30,
      "rows_produced_per_join": 30,
      "filtered": "100.00",
      "cost_info": {
        "read_cost": "10.52",
        "eval_cost": "3.00",
        "prefix_cost": "13.52",
        "data_read_per_join": "114K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ],
      "attached_condition": "((`nuie_scalesta_net`.`cscart_product_descriptions`.`product_id` in (95165,95166,95167,95168,95169,95170,95171,95172,95173,95174,95175,95176,95177,95178,95179,95180,95181,95182,95183,95184,95185,95186,95187,95188,95189,95190,95191,95192,95193,95194)) and (`nuie_scalesta_net`.`cscart_product_descriptions`.`lang_code` = 'en'))"
    }
  }
}

Result

product_id short_description full_description
95165
95166
95167
95168
95169
95170
95171
95172
95173
95174
95175
95176
95177
95178
95179
95180
95181
95182
95183
95184
95185
95186
95187
95188
95189
95190
95191
95192
95193
95194