SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e1ba6f1f07bcbf15a06753b4c73df255f2cb49a069516b05ae9269f109cc07c2' 
  AND token = 'sM1jmPIhhkkSiDvg8jcsFGaC79Zpz+IaYZzznvlySqA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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