MySQL:

IS_IPV4_MAPPED

Syntax:
IS_IPV4_MAPPED(expr)

This function takes an IPv6 address represented in numeric form as a
binary string, as returned by INET6_ATON(). It returns 1 if the
argument is a valid IPv4-mapped IPv6 address, 0 otherwise. IPv4-mapped
addresses have the form ::ffff:ipv4_address.

URL: https://dev.mysql.com/doc/refman/8.0/en/miscellaneous-functions.html

Example

mysql> SELECT IS_IPV4_MAPPED(INET6_ATON('::10.0.5.9'));
-> 0
mysql> SELECT IS_IPV4_MAPPED(INET6_ATON('::ffff:10.0.5.9'));
-> 1