DB Connect logs the execution time of the commands by default. You can use the following search for example to see the execution times of dbquery:
index=_internal sourcetype=dbx_debug (logger=DatabaseQueryCommand (action=executing OR "statement executed")) OR (logger=ExecutionContext "Execution finished")
| eval query_duration=tostring(duration/1000,"duration")
| transaction thread maxpause=30m startswith=(logger=DatabaseQueryCommand action=executing) endswith=(logger=ExecutionContext)
| table _time query database count query_duration
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