"at such-and-such a time, precisely then" is Тогда-то in Russian.
Тогда-то means "at such-and-such a time, precisely then" in English.
Listen to the pronunciationWord #2320 of 4,000 by frequency in Russian — level B2.
Тогда-то мы и встретились впервые на вокзале.
It was precisely then that we first met at the station.