SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '57c038b0b45ea729c9722096ebb652dc0808fb086dadb4cb4e209d70dc1f9980' 
  AND token = 'koRHydkt2eTRR4OUiDQ5a7qOGdgyfNpUg8byjViI+3g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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