Does anyone know why the time range picker here on the right side (set to Yesterday Jan 30) cannot affect my _time data field in the query result? How to link them?
That's because you re-evaluated _time in the third line shown in the screenshot to "created_at".
| eval _time = created_at
You data may have collected these events from Jan 30, but the field "created" has different values
Got it. Thanks for the explanation. So is there a way to modify the time filter to point to my timestamp which is created_at?
Yes. if you don't like your current _time at all, you can change your ingestion to use created_at as _time. (This is perhaps not the correct solution in most cases.)
At search time, you can use calculated field to calculate epoch time from created_at and name it _time.