SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c4459cfe0dae61aff6948620689145f2efa32e3dc9c6e6e5ffd02c50fd9ecda2' 
  AND token = 'SYtqim9FRxs585XVVl00sHqtOo3LliNxkQH4UHX2uvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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