SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0ed9977b82ffd0975b87f7e1e7667686361fbbcec4da80a9634691b43925835e' 
  AND token = 'Sy/IlXgnSkeycGw44eZObs4EinzDmMjw8GdCbJd5GN4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}