public MultiVersionedKeyQuery<K, V> fromTime(final Instant fromTime) {
        return new MultiVersionedKeyQuery<>(key, Optional.ofNullable(fromTime), toTime, order);
    }
Specifies the starting time point for the key query.
<p>
The key query returns all the records that are still existing in the time range starting from the timestamp {@code fromTime}. There can
be records which have been inserted before the {@code fromTime} and are still valid in the query specified time range (the whole time range
or even partially). The key query in fact returns all the records that have NOT become tombstone at or after {@code fromTime}.

@param fromTime The starting time point
If {@code fromTime} is null, it will be considered as negative infinity, ie, no lower bound
streams/src/main/java/org/apache/kafka/streams/query/MultiVersionedKeyQuery.java