SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd92383a25929adef050a41d68a71beb256e84b45c030df873a39abc18d7070db' 
  AND token = 'YQIGNFd1eYEfacFVsSmbepJEICEcJIJ8so7jP9sYPkA=' 
  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"
    }
  }
}