Thats the hexadecimal private key. You can obtain the 52 character and even the 51 character private key by using it.Or if I am wrong you may be referring to the public key which is useless.
Not sure about the hexadecimal private key. However, the public keys didn't come into use until BIP38 in 2015 (unless I'm wrong). If you mean extended public key that is. If not then it could be an address in some sort of encrypted format.
(BTW it's not hexadecimal as it wouldn't begin with a K if it was).