SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd6c9d655aa0bd2ff9b3d6ebd35c9f7ee4a28853e6dbf03e7ac55392bd0280101' 
  AND token = '/GVO1fIoIIhJL9J/JPZGzWvFaK+tY7jjBSdF5x5dss0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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