One of the most important criteria for successful website optimization is the domain name used by your website. If the domain name exactly matches the keyword you’re targeting, you are in a very good way. In this context also plays a big role domain extension (TLD) that tells which country is assigment to. Country of domain can be selected using the Google Webmaster Tools only if it is the domain type as .com, .net, .org, .eu etc…
If the domain name does not contain the keyword which you’re targeting then make sub domain, folder or file name with keyword name.
URLs should be short and clear for visitors as well for search engines.