SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1100c419c9fac66a2907757b99beb28dc9c779729f60b216fa47090bee8d69d8' 
  AND token = 'xwyKoAUUZYrxvygtAiYMGEP/ImVVDlAEK546Z3VGZx8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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