SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5c95686d59c26a062db665daee4c81b90f0faee91ca6a60c2e07c499773edea3' 
  AND token = 'xbWV+T42LIzdWN52VAQAonCddTDkkiqCDt7zeIUXLrU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}