SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1c719e2f4befdd82c9186cc50ae4624eaffbc667a3cb53c2e99d868a20e9681' 
  AND token = 'fd4s+wQWRSWbkMHgsgcw39Hg+gqJFTwUdIaicoE80f8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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