SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68c4fc5e01f43cf11a085bce7343284d967ed906ddce1b42184b4b2f8646121a' 
  AND token = 'stNDlRzT8UL5Hro/mWNYqOBQyXGzshQ2JlPLowlWWoI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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