SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ab613156406a5e2ad2cbd520a185da4ccfc8ccd530eca697fe663553e0299f95' 
  AND token = 'ATmtW3ksf9cvE9GVnttXkghrkcpRq6Y0VuOUtLGImbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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