All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It is an act of Sunnah in the Friday Prayer to shorten the Khutbah and prolong the prayer. It was narrated that the Prophet, sallallaahu ‘alayhi wa sallam, said: “Prolonging the prayer and shortening the Khutbah indicate one's religious understanding. So prolong the prayer and shorten the Khutbah.” [Muslim]
The limitation of the Khutbah duration to the extent of the long Mufassal Surahs is mentioned by many Hanafi scholars, although there is no textual evidence to support it, to the best of our knowledge. However, this is intended for approximation; and it is good. So, a ten-minute Khutbah is a good thing.
On the other hand, prolonging the Khutbah to last for forty-five minutes, as in the case of the mosque mentioned, first undoubtedly, this contradicts the Sunnah, and additionally, it is a reason for boredom and for the attendees' failure to benefit from what is said in the Khutbah.
Allaah Knows best.