Missing public key when checking signature of my emacs lisp package

["Дронов Евгений" <dronov-ep@yandex.ru>]

Greetings to GNU Emacs support! I'm making emacs-lisp package (library) and i want it to be uploaded to emacs default package-archive http://elpa.gnu.org  soon.
But before doing so i've decided to upload it to my local package-archive (directory on my computer) and check the experience that any person can get trying to install my package.

Unfortunately, when i try to install it from my local package-archive i get the message:


Failed to verify signature MyPackageName.tar.sig:
No public key for key-id created at 2016-10-22T23:42:29+0300 using RSA

I don't understand why it doesn't find public key. I've created my key-pair using "gpg gen-key" command. Signed my package .tar file with command "gpg -ba -o MyPackageName.tar.sig MyPackageName.tar". Copied output of command "gpg --export -a key-id" to clipboard. Pasted it in 'Submit a key' form in http://pgp.mit.edu/ and submitted - so my public key should be available for everyone right now. But signature - checking at the installation of my package fails. I don't understand , why?

Maybe my whole signing sequence is wrong, i don't know. Emacs-lisp packaging documentation doesn't say much about this. Emacs EasyPG Assistant also doesn't help because its basic signing commands give me .gpg-file signatures but it seems that
emacs package installator can only read .sig-file signatures. 

What am i doing wrong? Please help me!