Index scan timed out for count queries for 1M items

single node
kv+index+n1ql
primary index is gsi
example of query is:
cbq> select count from default where FareBasisCode is not missing;
{
"requestID": "a61299be-3e96-48c1-9cb1-084b5d8bdf17",
"signature":

{ "$1": "number" }

,
"results": [

{ "$1": 321105 }

],
"errors": [

{ "code": 5000, "msg": "GSI scan error - cause: Index scan timed out" }

],
"status": "errors",
"metrics":

{ "elapsedTime": "7m10.368738158s", "executionTime": "7m10.368613517s", "resultCount": 1, "resultSize": 36, "errorCount": 1 }

}

cbq> explain select count from default where FareBasisCode is not missing;
{
"requestID": "ec03dacf-ac43-4978-812e-c2ffb81ab4a4",
"signature": "json",
"results": [
{
"#operator": "Sequence",
"~children": [

{ "#operator": "PrimaryScan", "index": "#primary", "keyspace": "default", "namespace": "default", "using": "gsi" }

,
{
"#operator": "Parallel",
"~child": {
"#operator": "Sequence",
"~children": [

{ "#operator": "Fetch", "keyspace": "default", "namespace": "default" }

,

{ "#operator": "Filter", "condition": "((`default`.`FareBasisCode`) is not missing)" }

,

{ "#operator": "InitialGroup", "aggregates": [ "count(*)" ], "group_keys": [] }

]
}
},

{ "#operator": "IntermediateGroup", "aggregates": [ "count(*)" ], "group_keys": [] }

,

{ "#operator": "FinalGroup", "aggregates": [ "count(*)" ], "group_keys": [] }

,
{
"#operator": "Parallel",
"~child": {
"#operator": "Sequence",
"~children": [
{
"#operator": "InitialProject",
"result_terms": [

{ "expr": "count(*)" }

]
},

{ "#operator": "FinalProject" }

]
}
}
]
}
],
"status": "success",
"metrics":

{ "elapsedTime": "77.845754ms", "executionTime": "77.672745ms", "resultCount": 1, "resultSize": 2469 }

}

cbq>