SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '426b2f05a053d9f5405afd520e11239ed2a2278f143e956ab953161eae87e9cf' 
  AND token = 'VZxgAgmwMo0NhIa8Fl2v2DK8bhec24xlx9xvIvcVdKc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}