SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '09b3a59a4f297102db652054209e1db4b7b37d436d91197ee0041d3d8e12e243' 
  AND token = 'M6CDlcKRMif9UhRvcLPoM2kzTZgjlMLh5kqk87HvTAQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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