Any chance you recently upgraded to a very recent version of MC, or has your /etc/hosts file changed or been removed?
I experienced a similar thing on a recent installation of Slackware -current, and it was suggested to me that MC may be trying to resolve the machine hostname/IP incase it is going to be used to browse files on a network.
I'm not sure if that is correct, but I put my machine name into my hosts file, along with its IP address, and around the same time, the problem stopped. Now MC starts fast like it always did.
Best of luck,