SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1f350a5dce54f37c1d3fae061d8cc2aa328a27391ae298a37440f1b2b75e80c0' 
  AND token = '3UipTGjuY2hDVy4eyHTzpzJnUpv9iKLeoQZ6/VC7PYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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