SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b09b3020a045d64764ffd1c43e14755feb8c307dd253366ea63e95cdbd92e7a2' 
  AND token = 'm91kIzOc/WsegZsvHJwihau/2sX4exlO94SDl+zqQ0c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}