Censys expands queries to provide additional functionality. For example, the query a:zmap.io
executes a DNS lookup and expands to ip:141.212.120.90.
Your query was changed from:
parsed.tbs_noct_fingerprint: 676452d82c346f974618f19fbc17a06d47855bbf55f71304ef940ba5cb06e574 and precert: true
to
parsed.tbs_noct_fingerprint: 676452d82c346f974618f19fbc17a06d47855bbf55f71304ef940ba5cb06e574 AND precert: true
If this isn't what you intended, you can run your raw query without expansion.