Toyota engines can last forever if you take care of them. You should look into it as much as you can, but I wouldn't worry too much about the miles. If everything else is fine with it, that would be a good deal for a car that will get you good gas mileage and is reliable.
The car I drove until I bought my Echo two years ago was a 1989 Corolla. My brother is still driving it and it's up to 210,000.
However, I did get in a rollover accident last year in my Echo (it was totaled) and later found out that Echos have one of the highest rollover percentages besides SUVs which isn't really something that I even looked at.