SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c384dfc7f16e06882be1db9ba643cbb3c426ccfed82a27a5074b56f07b70755f' 
  AND token = 'oRpxBonwL2PkTgojHJaVjs/8PFWF+DfGgzjag1nD6sU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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