SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0544eda39f64aec2855f7158f3cd81c23bc580b3117d183cf7c9bab718d668af' 
  AND token = 'DSUxImvnWle9Abtbc0wg8fkmDyIqDZgjG0jmeYdn5kU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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