SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd699ccb4d794c761318486ba626940f02412182e08e85caa0a8ab41e5a14f0b6' 
  AND token = 'T/un3DpYjt9mWCHwp10D+/SLkYHMqcpp1z0IqoyNtVU=' 
  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"
    }
  }
}