Yes, you can publish more than one DKIM record on your domain. DKIM records will differ by the DKIM selectors in order email receivers can find the right record in DNS to authenticate emails by DKIM.
Multiple DKIM records are published if you use more than one email service provider to send email campaigns.
You can use the GlockApps free DKIM Record Checker to verify the validity of the DKIM record published on your domain.
Additionally, you can use the GlockApps DMARC Analyzer to find out if your messages pass DKIM authentication and alignment and determine the sending sources, which send unauthenticated emails.
Read more: Why DKIM Fails: 5 Steps to Fix DKIM Failure