SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c557af4f5740bcb5c40ce095d73ed4b49a96bbcb83ab2e874298b7546c538f' 
  AND token = 'AvXsetP+jPBV5uQVDZo90WclnDzYPCeKsDerhMrMhX8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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