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 (
    132035, 146031, 176251, 170832, 135554, 
    137799, 173327, 159342, 146762, 170252, 
    160755, 169265, 160662, 147699, 157878, 
    135946, 160157, 118469, 177483, 173028, 
    131244, 154982, 119478, 163555, 136384, 
    119286, 142795, 158710, 160433, 128081, 
    125912, 173014
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00260

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost": 0.0564324,
    "nested_loop": [
      {
        "table": {
          "table_name": "cscart_product_descriptions",
          "access_type": "range",
          "possible_keys": ["PRIMARY", "product_id"],
          "key": "PRIMARY",
          "key_length": "9",
          "used_key_parts": ["product_id", "lang_code"],
          "loops": 1,
          "rows": 32,
          "cost": 0.0564324,
          "filtered": 100,
          "attached_condition": "cscart_product_descriptions.product_id in (132035,146031,176251,170832,135554,137799,173327,159342,146762,170252,160755,169265,160662,147699,157878,135946,160157,118469,177483,173028,131244,154982,119478,163555,136384,119286,142795,158710,160433,128081,125912,173014) and cscart_product_descriptions.lang_code = 'en'"
        }
      }
    ]
  }
}