I have a table customers with a PK on the field LINK, which is unique

select * from customers where link = 'WWW0000010'

the stats say 12123 non-indexed reads were performed during the operation

Is this correct, or in other words, is this the way a PK is used?

The plan says PLAN( CUSTOMERS NATURAL)

The machine takes some strain, so I am almost sure a full table scan is
happening.

Any ideas or explainations would be appreciated.

TIA

Gary