ST_IsEmpty(g)

This function is a placeholder that returns 1 for an empty geometry
collection value or 0 otherwise.

The only valid empty geometry is represented in the form of an empty
geometry collection value. MySQL does not support GIS EMPTY values such
as POINT EMPTY.

ST_IsEmpty() handles its arguments as described in the introduction to
this section.

URL: https://dev.mysql.com/doc/refman/8.0/en/gis-general-property-functions.html

