SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8bc4ad727a866d80c807fa26b370842e6fc32562fe14e4c1146af7d41d4fc7ea' 
  AND token = 'QcrzXfZgzHILY5QGKShrrEIZUFP/6BBz95L4HOHnvwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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