SELECT 
  1 
FROM 
  q_lock_keys 
WHERE 
  key_id = '4a2eae1bff9942d3d2bff3e96647ef2d748de9b68e578084fed8745f34630faf' 
  AND token = 'onSc0I+ZGXZUY5fT8vHKWxg5PFOEHmWtYBRfqXpsVJ8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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