The exact date of construction of the monastery is unknown, but it apparently existed already in the mid-16th century.
The temple's name 'Maha Lok' could refer to one of the positive planes of existence in Hindu mythology being, Maharlok (Sanskrit: Plane of greatness), located above the plane of Heaven (Swargalok). It is also called the Devaloka, the fourth highest of the seven upper worlds. The Lokas, or Worlds, are described in the Vishnu Purana, one of the eighteen Maha Puranas, a genre of ancient and medieval texts of Hinduism.
Wat Maha Lok is in geographical coordinates: 14° 22' 14.25" N, 100° 34' 30.02" E.
The monastery shows on Phraya Boran Rachathanin’s map of 1926 CE. Phraya Boran (1871-1936 CE) was the Superintendent Commissioner of Monthon Ayutthaya from 1925 till 1929 CE but occupied important functions since 1896 CE in Monthon Ayutthaya.
References:
[1] Cushman, Richard D. & Wyatt, David K. (2006). The Royal Chronicles of Ayutthaya. Bangkok: The Siam Society. pp. 22-3.
[2] Ibid. p. 322.