SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '623496e90ddd8245ce653a5c5caa67bb5a96256e0fb90e0d48fb684b18b41de2' 
  AND token = 'Js/aVvzb2ACYKPQkmkKbN70COxHnehO+sv9e0JN4OXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00141

JSON explain

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