It is impossible to have more than two key pairs available for use at any given time, see Data Access Rotation :
[...] you can have two credentials in an active state at any given time so you can rotate them without affecting your application. availability. The AWM Security Credentials page displays the current status of each of the credentials that you can rotate. Possible states:
Active - can be used to protect AWS requests.
Inactive - cannot be used, but can be returned to the active state.
Deleted - can never be used again.
The first sentence is actually a little misleading if it is applied to key pairs in an inactive state, because they can be reactivated.
Once you delete the inactive key, you can create a new one.
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