Censys expands queries to provide additional functionality. For example, the query a:zmap.io
executes a DNS lookup and expands to ip:18.104.22.168.
Your query was changed from:
parsed.tbs_noct_fingerprint: 15e9c0510a59773bf1f0db8c63f32ad03429e600a0a53ef2da5f0cd3a3043f9e and precert: true
parsed.tbs_noct_fingerprint: 15e9c0510a59773bf1f0db8c63f32ad03429e600a0a53ef2da5f0cd3a3043f9e AND precert: true
If this isn't what you intended, you can run your raw query without expansion.