SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6aaf3201163dd98062a59b52986fad67cd8a4c8119400c6d9ccc0be2d8ccc5b6' 
  AND token = 'EzNjbO+IvqoD9DHnP/9Mm3B7LJ8xvJzz6SQ2ZHVSIIY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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