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.meta_keywords, 
  cscart_product_descriptions.meta_description, 
  cscart_product_descriptions.search_words, 
  cscart_product_descriptions.promo_text, 
  cscart_product_descriptions.unit_name 
FROM 
  cscart_product_descriptions 
WHERE 
  cscart_product_descriptions.product_id IN (
    3845, 2667, 2668, 2669, 2670, 3846, 3847, 
    3848, 3849, 3850, 6258
  ) 
  AND cscart_product_descriptions.lang_code = 'en'

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "13.25"
    },
    "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": 11,
      "rows_produced_per_join": 11,
      "filtered": "100.00",
      "index_condition": "((`gaseus`.`cscart_product_descriptions`.`product_id` in (3845,2667,2668,2669,2670,3846,3847,3848,3849,3850,6258)) and (`gaseus`.`cscart_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "12.16",
        "eval_cost": "1.10",
        "prefix_cost": "13.26",
        "data_read_per_join": "50K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description",
        "meta_keywords",
        "meta_description",
        "search_words",
        "promo_text",
        "unit_name"
      ]
    }
  }
}

Result

product_id short_description full_description meta_keywords meta_description search_words promo_text unit_name
2667 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
2668 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
2669 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
2670 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
3845 Bourdon tube pressure gauge with reed contact, housing diameter 63 mm and radial connection 1/4 NPT-M at the bottom at 6 o'clock. Housing diameter: 63 mm. Scale: see item selection. Material: stainless steel.
3846 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
3847 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
3848 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
3849 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
3850 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass
6258 Pressure gauge PI 50 mm Bourdon tube 1/4 NPT-M at 6 o'clock Kl 2.5 BC Housing diameter: 50 mm Nickel-plated brass