Censys expands queries to provide additional functionality. For example, the query a:zmap.io
executes a DNS lookup and expands to ip:188.8.131.52.
Your query was changed from:
parsed.tbs_noct_fingerprint: 468c8dd4aad1c0ed7eddb34af2d3a71d00ff073531f1b27f12cf494fe76388c1 and precert: true
parsed.tbs_noct_fingerprint: 468c8dd4aad1c0ed7eddb34af2d3a71d00ff073531f1b27f12cf494fe76388c1 AND precert: true
If this isn't what you intended, you can run your raw query without expansion.