As the private key part of the Key Pair should remain secret, Key Pair entries are normally protected by a password. In KeyStore Explorer such entries are described as being Locked and have a closed padlock displayed against them:
To access the private key the entry must be Unlocked by supplying the correct password. If an entry is successfully unlocked then an open padlock is displayed against it:
If a Key Pair entry is unlocked once during a KeyStore Explorer session it does not need to be unlocked again. A Key Pair entry may be unlocked explicitly or as part of an operation that requires the private key.
A Key Pair must be unlocked to utilize it for operations such as digital signing or to view or export the private key.