SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '704b645a38cd22cc870b4c784e9e3d835c4843049c427654823bbbefaabc7c92' 
  AND token = 'm1otCz8ketC7vujOvn7d99WWTP+IE0XChCEsrVPNvjQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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