Here is some useful commands to display a domain Time To Live (TTL) using the DIG command (which is usually included within “bind-utils” package).
To display the full information :
dig +nocmd +multiline +noall +answer any domain.tld
To display the short, default answer :
dig +nocmd +noall +answer domain.tld
NOTE : Replace “domain.tld” by the domain you want to query.