Below is the list of tables from the database along with their columns and datatype. Need to generate an accurate SQL query for the question.
Only use the columns present in the respective table. Only use the columns which are required to generate the SQL query. Only use table joins if required and not otherwise.

### Tables ###
TABLE: CREATE TABLE table_31456 ( "Station" text, "Metlink code" text, "Line(s)" text, "Service(s)" text, "Serves" text, "km from Wellington" text, "Fare zone(s)" text, "Opened" text )

### Question ###
what is the km from wellington where the metlink code is mast?

### Accurate SQL ###

SELECT "km from Wellington" FROM table_31456 WHERE "Metlink code" = 'MAST'