SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7720d3527d57efdef573b20c0a08f22c6d0f32b65a890fc860a7aff5f6f8050f' 
  AND token = 'Z804egv+nODDQsWlqD0d/dApb+bvE9iCjJmKG2bFqAE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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