SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7ece473be565414e38ade8b7a1d955d40c8cf7b85c4b2eadae4cfc413e4904ee' 
  AND token = 'WvXgxr2LXbivVzTRIWkTEtPZjECVCLJmWIwE9JCTXYU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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