SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c23e9030b52bb3fa988776b315d042314105867218540f99743ab41e045df674' 
  AND token = 'H6U7DgJ0cMylmC5SBBBCb6vu62YCcXegtHTEt4UsuJM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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