A nonce is a “number used once” to help protect URLs and forms from certain types of misuse, malicious or otherwise. WordPress nonces aren’t numbers, but are a hash made up of numbers and letters. Nor are they used only once, but have a limited “lifetime” after which they expire. During that time period the same nonce will be generated for a given user in a given context. The nonce for that action will remain the same for that user until that nonce life cycle has completed.
so it used for security reasons ,and your idea to have fixed one against that concept ,so as @Jacob Peattie said why then have a nonce at all??!