Allah is Al-Muqaddim (The Expeditor).
He speeds up matters and accelerates their pace. So not everything has to be delayed. Allah not only can, but in fact, does speed up matters that are usually delayed otherwise. Remember the time when you got something so “surprisingly” quickly and easily even though “usually” it takes so long? Perhaps a visa, a job, marriage or something else?
Yup. The “Surprising” part is what Al Muqaddim is there for.
The messenger of Allah (peace be upon him) once prayed for rain, and said”…quickly,and not delayed…”(Ibn Majah)
So you can ask Allah to answer your prayer quickly,contrary to the popular misconception that arises from another hadith that says your dua will be answered as long as you are not hasty (that is, if you are hasty it will not be answered).This happens if one makes dua and seeing it unanswered,s/he stops asking.
The prohibition is from the hastiness that causes one to leave dua altogether getting disappointed. Otherwise, it is actually a sunnah to ask for a quick response from Allah.