Hello Jakob,
You’ll find this string registered for localization with the text domain called “themeblvd_front” — You’ll want to contact WPML support for help using their plugin to translate the text strings of your theme and plugins. I believe they have a String Translation addon for WPML that you can use to quickly translate these items through your WordPress admin panel.
So, to sum up, when using WPML’s String Translation addon, the text domain “themeblvd_front” is where you’ll find this text string along with all other text strings of the theme that appear on the frontend of your website.