SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cb6ba6c04d882c2add376eb46aa2e192288b848e77bf3dbc48008cd212b82512' 
  AND token = '2s9iRcRUM+qgdZ5TvruE5CbKVg9BkkFLrnJ+hfibR9o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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