SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4f7671ee19bcb1d110b6fb88f9787fbe1c567c7764e6d9b0e66e48b20893a716' 
  AND token = 'nKG1XsPwPTSufLi/6KJ5xxzTSLfHdFamy5fHZ181NKM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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