The last time the international airport of Beirut (Rafic Al-Hariri) was attacked by Israel was in July 2006. Direct flights from Iran to Beirut have been taking place for years and two Iranian airlines maintain a regular flight route to this day.
The Revolutionary Guards uses the regular Iranian civil airlines and their crews as a cover for the activity of smuggling weapons to Syria. It is a reasonable estimate that direct smuggling in this way was also carried out to Lebanon.
As far as Hezbollah is concerned, the airport is a strategic asset from both a military and civilian aspects. Its people de facto control what is done there. Hezbollah uses the airport itself and its surroundings for its military needs.
For example, we know about weapon launch and storage sites, with emphasis on the Fatah 110 missile array, so that Hezbollah itself has made the airport area a potential attack site.
