SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3ff9d929be1a95694a9c021c6b728b85948f85d7f8de62090dd61ecf4a725489' 
  AND token = 'jwa1KlPxe0DtxMZ8CfxmjFPVRYqgGNRtwnbjEDK+UOg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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