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 (
    19549, 19550, 19551, 19552, 19553, 19554, 
    19555, 19556, 19557, 19558, 19559, 
    19560, 19561, 19562, 19563, 19564
  ) 
  AND cscart_product_descriptions.lang_code = 'ru'

Query time 0.00037

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 (19549,19550,19551,19552,19553,19554,19555,19556,19557,19558,19559,19560,19561,19562,19563,19564) and cscart_product_descriptions.lang_code = 'ru'"
    }
  }
}

Result

product_id short_description full_description unit_name
19549 Cover assembly - luggage tray, right<p>Part number 85743G9530NNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19550 Trim Assembly - Covering Shelf<p>Part number 85910G9500</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19551 Cover Assembly - Luggage Floor Front<p>Part number 85760G9500NNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19552 Trim Assembly - Covering Shelf Center<p>Part number 85930G9500</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19553 Trim assembly - rear transverse<p>Part number 85770G9500NNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19554 Lamp Assy-Luggage Compartment<p>Part number 92600T6000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19555 Socket Assembly-Accessories<p>Part number 95120AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19556 Cover assembly - accessory socket<p>Part number 95122AR000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19557 socket<p>Part number 95123J3000</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19558 Bolt-Washer Assembly<p>Part number 1125106163</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19559 Trim Assembly - Front Pillar<p>Part number 85810G9600VNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19560 Trim assembly - front pillar, right<p>Part number 85820G9600VNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19561 Trim assembly - center pillar upper, left<p>Part number 85830G9100VNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19562 Trim assembly - center pillar upper, right<p>Part number 85840G9100VNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19563 Knob-Height Adjust, Left<p>Part number 85834G9000VNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>
19564 Knob-Height Adjust, Right<p>Part number 85844G9000VNB</p><p>If you are not sure about compatibility, please contact us in advance to confirm the part number.</p>