SELECT 
  q_product_descriptions.product_id, 
  q_product_descriptions.short_description, 
  IF(
    q_product_descriptions.short_description = '', 
    q_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  q_product_descriptions 
WHERE 
  q_product_descriptions.product_id IN (
    557, 558, 559, 560, 561, 562, 563, 564, 
    515, 516, 517, 518, 519, 520, 521, 522
  ) 
  AND q_product_descriptions.lang_code = 'en'

Query time 0.00056

JSON explain

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    "table": {
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        "product_id"
      ],
      "key": "PRIMARY",
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      "key_length": "9",
      "rows_examined_per_scan": 16,
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      "filtered": "100.00",
      "index_condition": "((`portal`.`q_product_descriptions`.`product_id` in (557,558,559,560,561,562,563,564,515,516,517,518,519,520,521,522)) and (`portal`.`q_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "35.21",
        "eval_cost": "3.20",
        "prefix_cost": "38.41",
        "data_read_per_join": "61K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}

Result

product_id short_description full_description
515 <p>Gucci launches its new perfume Gucci Bamboo in spring 2015, named after the already existing collection of accessories. The fragrance apparently reflects confidence and femininity. It is designed for modern women of character that is multifaceted; the fragrance is intense, graceful and gentle at the same time. The composition is floral - woody. It opens with citrusy accords of bergamot leading to the exotic floral heart of ylang-ylang, Casablanca lily and orange blossom. Intense notes of sandalwood, Tahitian vanilla and amber form the base. The face of the perfume is actress Gal Gadot. The bottle design blends delicate sensibility with strong lines. Glass art deco bottle in the shape of a diamond is contrasting with soft pink liquid. Polished silver cap gives the Bamboo signature.</p>
516 <p>Gucci launches Gucci Bloom Nettare Di Fiori as a sensual and darker interpretation of the original, with additional notes of rose, ginger, osmanthus and patchouli. "Intensely sensual and feminine, Gucci Bloom Nettare di Fiori celebrates the intimate and authentic character of a woman. Rose and Osmanthus flower resonate in an enigmatic, woodier blend together with the notes of the original Gucci Bloom."</p>
517
518
519
520
521
522
557
558
559
560
561
562
563
564