The public EOS key which will be valid is the one that you would have linked (i.e. mapped) to your Ethereum wallet. You can only link one EOS public key to another Ethereum public key I believe. Here's an article how to do just that. It was created for the Exodus wallet, but you could follow most of the steps in detail and replace the Exodus related items with the wallet you're using and the method you normally use to open your MyEthereumWallet: http://support.exodus.io/knowledge_base/topics/ive-received-eos-tokens-in-exodus-how-do-i-register-them