SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '334fd2906f409680f9cbbd6f2ea990a8e0cee6d54369468a5cc60c632b64c300' 
  AND token = 'A2yXjNPKwQZTQt5+dddWdl6pOAO01DIWU7q0H+osjGI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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