SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b071b36c124dd5b6bcb2502b2722dcdcc496e743e4c9ba1faeabc83eff4b59af' 
  AND token = 'AZ0l1B7oITklAXjWQQn+cHSYFdkrW7fVoId/9aXNhGM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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