SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eabf322bbcf17328c38438dda798370f544c8de003b607efe1b5ece541caac36' 
  AND token = 'HMaD3ScuB0SmjuzzghU8w+qS8A581O/uZu/0XU61sz0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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