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 (
    19885, 19886, 19887, 19888, 19889, 19890, 
    19891, 19892, 19893, 19894, 19895, 
    19896, 19897, 19898, 19899, 19900
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00053

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "table_name": "cscart_product_descriptions",
      "access_type": "range",
      "possible_keys": ["PRIMARY", "product_id", "idx_product_lang"],
      "key": "PRIMARY",
      "key_length": "9",
      "used_key_parts": ["product_id", "lang_code"],
      "rows": 16,
      "filtered": 100,
      "index_condition": "cscart_product_descriptions.product_id in (19885,19886,19887,19888,19889,19890,19891,19892,19893,19894,19895,19896,19897,19898,19899,19900) and cscart_product_descriptions.lang_code = 'en'"
    }
  }
}

Result

product_id short_description full_description unit_name
19885 Protector-heat front, left<p>Part number 28791T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19886 Protector-heat front, right<p>Part number 28792T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19887 Protector-Heat Center<p>Part number 28793T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19888 Protector-heat rear, left<p>Part number 28795T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19889 Protector-heat rear, right<p>Part number 28796T1000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19890 Electronic control unit (ECU)<p>Part number 391103N731</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19891 Sensor-Crankshaft Position<p>Part number 391803N900</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19892 Sensor Assembly - Oxygen<p>Part number 392103NTA0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19893 Sensor Assembly - Oxygen<p>Part number 392103NTB0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19894 Sensor Assembly - Oxygen<p>Part number 392103NTC0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19895 Bracket-connector, right<p>Part number 392113NTA0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19896 Bracket-connector, left<p>Part number 392113NTB0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19897 Sensor Assembly - Knock<p>Part number 392503NTA0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19898 Extension wire - CMPS<p>Part number 393523N100</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19899 Cover assembly - rust sensor, left<p>Part number 392533NTA0</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19900 washer<p>Part number 97749B1242</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>