Use XSLT to filter source XML to destination XML

Due to a production issue a bunch of data was corrupted. The good news is that I have all the data in an XML file which happens to be in the same format as the input to submit data changes. The problem I have is one record takes a while to process. My "clean master" has >20,000 records, and only 530 have been corrupted. I have a key field to identify the record I want to include in my destination. How can I include in an XSLT to output a node only if it is in a list I specify? I do not care if I hard-code the list in the XSLT.

<recordSet>
  <record>
    <key>123</key>
    <val1>abc</val1>
    <val2>def</val2>
   </record>
  <record>
    <key>456</key>
    <val1>hij</val1>
    <val2>klm</val2>
   </record>
  <record>
    <key>789</key>
    <val1>nop</val1>
    <val2>qrs</val2>
   </record>
 </recordSet>

Let's say I only want records with key 123 and key 789. Thank you.