AccessDenied on AWS Athena

When I run a simple select * query on AWS Athena I get an access denied error.

The query is:

select * from sensor.sensordata

The Schema is:

CREATE EXTERNAL TABLE sensor.sensordata (  sig string,  `data` struct<`iat`:timestamp,  `sub`:string,  tMax: float,  tMin: float,  `tAvg`: float,  `hAvg`: float,  hMin: float,  hMax: float>) ROW FORMAT SERDE 'org.openx.data.jsonserde.JsonSerDe'LOCATION 's3://mybucket/data/';

The error I get (IDs shortened) is that a file can not be read:

com.amazonaws.services.s3.model.AmazonS3Exception: Access Denied (Service: Amazon S3; Status Code: 403; Error Code: AccessDenied; Request ID: B0048904...; S3 Extended Request ID: CKchfW8...), S3 Extended Request ID: CKchfW8... (Path: s3://mybucket/data/sensor=01235EFD886C7DF1EE/t=1561513414.json)

However I even made the bucket policy public for everyone:

{"Version": "2008-10-17","Statement": [    {"Effect": "Allow","Principal": "*","Action": ["s3:PutObject","s3:GetObject"        ],"Resource": ["arn:aws:s3:::mybucket/*","arn:aws:s3:::mybucket"        ]    }  ]}

Beside the bucket policy I also have in the ACL the standard full access to the bucket owner, which is the same Account I run my Athena Query from. I run my query in the AWS Management Console.

Not sure if related: AWS Glue Crawler is not able to read the files. But can list them, I get an error for every file.

What can I do to make the query work?