SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '313e8f7898bbf824e498d7277eb22e726d64bd0a9b63958e87c6f71084f28841' 
  AND token = 'QsIZx+wSyzYsd/Go4FomBVaJp/tAzojDXvsBZkkY5mo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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