Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '391921408cce19913625eb07b68607afbb65b9a226f468cc1225301820e09b41' 
  AND token = 'SLQfXfPmrh+jByMdMVDFLQlbBdoRfOgIiVV0jzEoZfQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00049

JSON explain

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