SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf80c718c2b9b86a5c8a1961edd2451ffebbf6f1186cf0283304f895c2dd9eae' 
  AND token = 'cJkSVvHVjCFi+mDlCy9xUkg1+rHLtNibtZYFqw0vmKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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