SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '856aa65ec1e80a04697739e0d690974f25acb97b74c93f4f45797352462ac228' 
  AND token = 'C14pMWnNWjIlRz9GvPs3Qv/3XsaXK+4ZdtwPhE6WLFc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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