Keychain issues and strange behavior

I have been getting some strange behavior in Safari on my MacPro. I am still running OS 10.9.5 due to some old software we still need to run. When trying to trace down my freezing safari issue, I noticed some strange things in the console related to Keychain, like this:

secd[408]: SecErrorGetOSStatus unknown error domain: com.apple.security.sos.error for error: The operation couldn’t be completed. (com.apple.security.sos.error error 2 - Public Key not available - failed to register before call)

secd[408]: securityd_xpc_dictionary_handler Keychain Access[66705] DeviceInCircle The operation couldn’t be completed. (com.apple.security.sos.error error 2 - Public Key not available - failed to register before call)

When I look in the Keychain access app, I notice I have quite a few expired certificates. However, I am not familiar with how keychain works and know very little about SSL and certificates, so I have yet to try anything other than "Keychain First Aid", which found no errors. Can I safely delete all my expired keychains? I don't really know where to start on this issue, but it seems to be getting worse all on its own. Any help or information would be greatly appreciated!

Thanks all