SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b97ca3d3d660e6ce2d159dbfd01d72e458fad0502a125a69cd06213f5e21f8f0' 
  AND token = 'ojFRY8DlMawPmSkFg2NrZ4+nrImAhSC8waf0FA9pMmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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