From the actual order:

Протокол № 41 заседания Президиума Верховного Совета РСФСР 5 февраля 1954 г.

Учитывая общность экономики, территориальную близость и тесные хозяйственные и культурные связи между Крымской областью и Украинской ССР, Президиум Верховного Совета РСФСР постановляет:

Передать Крымскую область из состава РСФСР в состав Украинской ССР.

Настоящее постановление внести на утверждение Президиума Верховного Совета СССР

My shitty translation:

Protocol #41 of the meeting of the Presidium of the High Soviet Russian SFSR of February 5th, 1954.

Taking into account the economic unity, territorial proximity, close industrial and cultural ties between Crimean Oblast (region) and Ukrainian SSR, the Presidium of the High Soviet Russian SFSR proclaims:

Transfer Crimean Oblast from Russian SFSR to Ukrainian SSR.

This proclamation to be entered for ratification by Presidium of the High Soviet of the USSR.

Basically, it made sense geographically, politically, economically, and from an administration standpoint. Not like there was any inkling in 1954 that the USSR would fall apart and the current issue would arise.

Another reason, while less documented, was the commemoration of the 300th Anniversary of Pereyaslavskaya Rada, which was a meeting of the Hetmans (leaders) of the Zaporozhye Cossacks in 1654, where it was decided to unite the territory of Ukraine with Russian Tsardom.