SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '67ac06209048183a179a42378fd0e42517eb32c368af8ba1299daa9ccd05f6ce' 
  AND token = 'ePTcMgpnPflOC0iM+apBsSQ1gJj/XjEgcaHCpKoiCDg=' 
  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"
    }
  }
}