SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fa5661fe95fe45531a0f60bd01d1f12ef30f2e92f4f585bfc98957d4cd2b133d' 
  AND token = 'lS1nAGA6TBQvvPX+qPqSOqO4xAGpwh1AQVf5+tUdVB4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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