SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4703d9c679becc4f8f8ffe27f62777914335bfd7ad0777a6c87487ea12916284' 
  AND token = 'NaJOF866MOrp+kk6REAjFioSRSrLs8Tfv2Y6eL0n9aU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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