SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '527a20baa961d965844b57b56625825ee86df724bcce75b55558d1b11f6edfe0' 
  AND token = 'GzcbkMOgMzhGZd6eHfxSffHsEXrIQD8FtCd7WYs99uU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00010

JSON explain

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