At least you can create a new one and post the public key on nostr. 

 Or you can renew 

 I'm going to need a moment to pull that master key and do what needs to be done on an airgapped machine. 

 you are probably overdoing it 

 I’m obsessed 

 As long as you can still edit the expiration date and republish the key to the key servers your key is still good! 

 my nostr key expired today 

 Wait? Huh?  

 yeah I leaked it so I could rotate keys 

 I don't understand why though? Shouldn't that be private?  

 my nsec is private until I want to rotate to a new one 

 I'm learning something new. 
Synapses be firing off right now.