SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'acfdf3ac748001670b1a263d323969f7c96423de044e0600350a45649ea5c9d8' 
  AND token = 'D5OLqvKHtnVz7yH/UdQKMlPZLYxzYI3B/xJ5eXQQWfs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00055

JSON explain

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