Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '24c1999f37dc1d1a570a346dbe2cd22c09937b3ffafaa2e8e7fcb031f232261f' 
  AND token = '4JqsRnhMf+MIY6rbaOYu79aHSXigkGCuY1TlKq21Mpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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