SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cef2f8353d30170626762fac29f0e441f7f491ff4b54666d030bed3967b41085' 
  AND token = 'bOTGuOSCASxy+/+vPSovgiECuQ9AqNzc3VhUM8LbTjk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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