The easiest way is to split the column first using separate() and " " as separator and then combine the date back with mutate().
library(tidyverse)
df = data.frame("Col1" = c("2 1 NDUyMg== Mon Jul 01 10:18:13 2019",
"2 1 NDUyMg== Tue Jul 02 11:34:16 2019"))
df_sorted = df %>%
separate(Col1, into = c("ID1", "ID2", "License",
"Day", "mon", "date_day",
"Time", "year"),
sep =" ") %>%
mutate(Date = paste(date_day, mon, year, sep="-")) %>%
select(ID1, ID2, License, Date, Time)
df_sorted
ID1 ID2 License Date Time
1 2 1 NDUyMg== 01-Jul-2019 10:18:13
2 2 1 NDUyMg== 02-Jul-2019 11:34:16