All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ʻalayhi wa sallam, is His slave and Messenger.
The speed of reciting has no effect on the validity of prayer, whether in reciting Quran or other Thikr (expressions of remembrance of Allah) of the prayer, unless the speed affects the proper pronunciation of the letters or changes their intonation (diacritics).
Speed with proper pronunciation and intonation is permissible, even in reciting the Quran inside or outside prayer. Ibn Al-Qayyim wrote, “Scholars held different opinions as to whether it is better to recite the Quran slowly and settle for reciting fewer verses or recite it quickly to be able to recite more verses. There are advocates for both opinions.” [Zaad Al-Maʻaad]
Hence, it is permissible to recite other than the Quran quickly in prayer with greater reason.
Allah knows best.