SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd2cbed74c973b825d758218a96975cf06c8f32a8227bf0fc443312fd40dbbd93' 
  AND token = 'EMtaUg/a410lq9xU0WVKIXQTj/upuS0+NJLjhkAdDCg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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