SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '55c088376827363d24c27a0a2bb4acb5196ccf6160de90a48a0c2d02b15d3fef' 
  AND token = 'h/9eb+e7cxqaDfpN92OSn/NSdwO1pWLHh5fGsrHRKbE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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