1. Iranians are not going to launch an attack on Turkey.
2. Turks are not going to initiate an attack on Iran.
3. The borderline between Turkey and Iran is essentially one of the oldest mutually recognized borders between two neighboring countries and stands as the oldest boundary in the Middle East for a reason.
4. Even if a single Iranian missile strikes Turkish territory, it won't have significant implications unless there's a consistent pattern. No one in Ankara is going to invoke Article 5 for just one missile.
5. Why the hell should Iran in this difficult times attack Turkey in the first place? What makes people think that would happen? Their entire foreign policy has always been very rational, even too rational one might say.