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_45 ( "Scheme" text, "Tariff code" text, "BTs retail price (regulated)" text, "Approx premium" text, "Prefixes" text )

### Question ###
What prefixes are priced at pence per minute, fixed at all times with a premium of 3p/min?

### Accurate SQL ###

SELECT "Prefixes" FROM table_45 WHERE "Scheme" = 'Pence per minute, fixed at all times' AND "Approx premium" = '3p/min'