SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dca5333822c1ca2bf42e126b8e6c65218ea43543e22bcf9d6899717746aee1b0' 
  AND token = 'WnR/GNEaO/gpcNKrQfmnbDGiIKtij2dYIy/DoQbbMNw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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