Checking if any key pressed in console application C#

I need to check if any key is pressed in a console application. The key can be any key in the keyboard. Something like:

if(keypressed)
{ 

//Cleanup the resources used

}

I had come up with this:

ConsoleKeyInfo cki;
cki=Console.ReadKey();

if(cki.Equals(cki))
Console.WriteLine("key pressed");

It works well with all keys except modifier keys - how can I check these keys?