SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e44f0852b3228cadda1bd08b876d512ab9461a344cfc9fc330dff106e8b7cb09' 
  AND token = 'Yp7tle3kQRlx5iNfvuRiGYUMr4Uvryh0cLgrxvgthy8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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