SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1a95d725854865978abc567c30c8dfc701cc8a4b0304b01249f5a43156a85f3b' 
  AND token = 'ljZJvFcQloj1cNyKPRo3zB6TdcSbW8ccUFSF7tKo04w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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