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SELECT 
  jmj_product_descriptions.product_id, 
  jmj_product_descriptions.short_description, 
  IF(
    jmj_product_descriptions.short_description = '' 
    OR jmj_product_descriptions.short_description IS NULL, 
    jmj_product_descriptions.full_description, 
    ''
  ) AS full_description 
FROM 
  jmj_product_descriptions 
WHERE 
  jmj_product_descriptions.product_id IN (
    1651, 1680, 1650, 1658, 1669, 1674, 1677, 
    1655, 1671, 1644, 1665, 1652
  ) 
  AND jmj_product_descriptions.lang_code = 'en'

Query time 0.00076

JSON explain

{
  "query_block": {
    "select_id": 1,
    "cost_info": {
      "query_cost": "28.81"
    },
    "table": {
      "table_name": "jmj_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": 12,
      "rows_produced_per_join": 12,
      "filtered": "100.00",
      "index_condition": "((`jmj_test`.`jmj_product_descriptions`.`product_id` in (1651,1680,1650,1658,1669,1674,1677,1655,1671,1644,1665,1652)) and (`jmj_test`.`jmj_product_descriptions`.`lang_code` = 'en'))",
      "cost_info": {
        "read_cost": "26.41",
        "eval_cost": "2.40",
        "prefix_cost": "28.81",
        "data_read_per_join": "45K"
      },
      "used_columns": [
        "product_id",
        "lang_code",
        "short_description",
        "full_description"
      ]
    }
  }
}

Result

product_id	short_description	full_description
1644		<p></p><h1>Boys Comfort Fit Shepherd Checked Spread Collar Cotton Casual Shirt</h1>
1650		<p></p><h1>Boys Mock Collar Solid Casual Lightweight Padded Jacket</h1>
1651		<p></p><h1>Boys Notched Lapel Collar Comfort Fit Velvet Single Breasted Blazer</h1>
1652		<p></p><h1>Boys Sequined Embellished Notched Lapel Single-Breasted Five Piece Party Suit</h1>
1655		<p></p><h1>Kids Waterproof Double Coating Reversible Hooded Rain Jacket</h1>
1658		<p></p><h1>Boys Relaxed Fit Mid-Rise Jeans</h1>
1665		<p></p><h1>Boys Chino Shorts</h1>
1669		<p></p><h1>Boys Woven Design Embroidered Sequinned Mandarin Collar Kurta</h1>
1671		<p></p><h1>Boys Embellished Woven Design Indowestern Sherwani</h1>
1674		<p></p><h1>Kids-Boys Embroidered Dupion Silk Kurta Sets</h1>
1677		<p></p><h1>Boys Woven Textured Mandarin Collar Nehru Jacket</h1>
1680		<p></p><h1>Boys Gold-Toned Embroidered Dhoti</h1>