SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f93c3246d5d5152c416aaa8bafdd9d1d9ad59ac4d89aae4dc183295efb40ef47' 
  AND token = 'B1QMgKEVKqBCN1MXrKujJROHY7+pZeKEJBtIjgsL1QU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00051

JSON explain

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