SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '480f03e91d348ada4dc92063a5cfec25789482db4f86b45eb66f673bca835696' 
  AND token = 'Qou/WnsQIZRtCiw1czkEaSxbYvHuIeFSGU5XUG81zIs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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