meaning of a KEY in CREATE TABLE statment in mysql

It is simply a synonym for INDEX. It creates an index with the name ndx_PickupSPC on the columns specified in parenthesis.

See the CREATE TABLE syntax for more information.

Key and index are the same. The word Key in the table creation is used to create an index, which enables faster performance.

In the above code, Key ndx_PickupSPC means that it is creating an index by the name ndx_PickupSPC on the columns mentioned in parenthesis.

It's just a non-unique index. From the manual

KEY is normally a synonym for INDEX. The key attribute PRIMARY KEY can also be specified as just KEY when given in a column definition. This was implemented for compatibility with other database systems.