Here you will find a link to the oficial International Trademark Search in the World Intellectual Property Organization (WIPO). In the same you can find identical trademarks to the one you look for but keep in mind that not only identical trademarks are an impediment to register a trademark but also similar trademarks are. To locate all relevant trademarks you should hire professional services to perfom a complete search before applying for registration of your International trademark search.
If you wish to register an International trademark, is also advisable to hire the services of a professional who not only does the application correctly mark but also offers a surveillance service.