SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '598b57092625ff091d7701b11ceb31cee8ab42993d04a2c8e668fa76fd72184f' 
  AND token = 'XGQ/MlVCJDN409GH1kOjXVsSeHFN7luEbiuhrMwpnzk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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