Hi man, I dumped private keys (there are 700+ not to include reserved addresses). So, regarding your question, - I've got transactions on multiple addresses.
I imported my keys to Electrum, but it's synchronizing already 24 hours. Is it ok?
No, that doesn't sound OK. Electrum is an SPV wallet, which means there is
not really any synchronizing[1] needed, atleast not one that takes 24H.
Either you have a really crappy internet connection, or there's something wrong with either
I. your PC/Network settings/firewall,
II. your wallet. (Outdated, corrupt, (fake version?(unlikely)).
III. The server you're connecting to on Electrum itself. Please try switching that up as well.
Please verify that you're using the latest version of electrum, and that you're using the right version. (Checksum matching, verify the signature.)Didn't read the fact that you have over 90k transactions...

My bad. That could be a big factor in why it won't sync, but it's still something i've never heard happening before...