SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c3d7c042a7871b555a959092155e133b90471ceb2a0bdbf094ca5b3fcb236811' 
  AND token = 'jjxS618hdnpRWxNsyJFm4zJ/KcGiKrQBzR3EMCh30jo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}