SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d5fa1b501deb7b4dd91d33a2e2b3b05626870cb773467addb08540ae5e1aae' 
  AND token = 'RqKJxJAvd/SxTmrFEitqghlHHwT3JbfmswIJevPjKQw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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