SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a05d420aa82e7093d2f3d2624a87c29588afd487948d53df22a19ddfe8ab281' 
  AND token = '1PLwG5WAsDuoZo0AwA/UOWqAclvvSwoqDzGkUgi/4E0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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