SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '01557c605afb273146abfb332bda35ad18d73858f25fd1ab331e5d19ba3be766' 
  AND token = 'dq1coQzablvYaRKOvCaZTIGgd52n71iqm7XBls69rdg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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