SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bf6646d511bdcbaf100507b1598290376db0f898f609b2709a9cd8e45a054cb' 
  AND token = 'hFQbanEldjZDqkzVZZELHdXfkh9a7CRE17Eagh91VfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}