SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'af7ae5f6e99f9375dad42e24c4b7ee7383532cc06690b40f90bc98ea31ae37d8' 
  AND token = 'w8lxv4VYwvUQ72vdkBIdqSxrj2wg6WdXd+W7ZbruGwg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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