SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0caea90a0b21892f8ef7d5d4c2b940492ae663ff16bb6d5c319e812aa862696' 
  AND token = 'bCNqmBksBOx+22IhX8oAz34GKvxJlui9bNIl7CXKZwc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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