SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa85eaa9ca939c46024c748b18318024cacb1e631acbb2a3b3565b516f6c5d34' 
  AND token = 'eIZPnCUUICo0QoDYuKxQBOJi7FDtRDGoAZiIEZBmMvI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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