SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8054c798433a1197bb3b426b81e73b66d5ff35963697edbbf68e554221ba426a' 
  AND token = 'OrpXAm0aHtVDHw3phIhvoFCwLxT+FAlRevJ8DoywZBM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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