SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5987d2b8ddd067cf7ad871b69409a94640ca5cc0e32a2e2ad5f5c7a255847bdd' 
  AND token = 'Z7GDmSK/vjygY0qBrOqUDdzJyONyO+efvcpCBKEJGzs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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