SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6c48d5fbfbfa12916d318a593899ea9709a9be1cb2043d9e1a5684c220e7edd4' 
  AND token = 'lh7YRhLBbPIY0hROD/qrF/UtrhbyrGf+qg5+F+qqX/I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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