The query below lists tables that are not referenced by foreign keys.

See also:
Query
select 'No FKs >-' as foreign_keys,
    tab.table_schema as database_name,
    tab.table_name
from information_schema.tables tab
left join information_schema.referential_constraints ref
          on ref.unique_constraint_schema = tab.table_schema
          and ref.referenced_table_name = tab.table_name
where tab.table_type = 'BASE TABLE'
      and tab.table_schema not in ('mysql', 'information_schema',
                                   'performance_schema', 'sys')
      and ref.constraint_name is null
     -- and tab.table_schema = 'your database name'
order by tab.table_schema,
         tab.table_name;
Columns
- foreign_keys - symbol indicating the lack of FK references
- database_name - database (schema) name
- table_name - table name
Rows
- One row: represents one table
- Scope of rows: all tables in a database (schema) that are not referenced by foreign keys
- Ordered by: database name and table name
Sample results

 
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                     
                                                                 
                                                             
                                                             
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                                 
                                                             
                                                             
                                                             
                                                             Rene Castro
                                                                        Rene Castro
                                 MariaDB
                                                                MariaDB
                                 SQL Server
                                                                                                SQL Server
                                             Azure SQL Database
                                                                                                Azure SQL Database
                                             Snowflake
                                                                                                Snowflake
                                             Amazon Redshift
                                                                                                Amazon Redshift
                                             IBM Db2
                                                                                                IBM Db2
                                             Teradata
                                                                                                Teradata
                                             Vertica
                                                                                                Vertica
                                             PostgreSQL
                                                                                                PostgreSQL
                                             MySQL
                                                                                                MySQL