SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'af97407c875958513ccccf0f8bba7e2669b34f230489687e976474635db8344e' 
  AND token = 'WVlGZtVIDjPfopXLMearC2oYKT4HT+dZWrFDGIhO1sY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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