SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '401483e9091e1b6e9169b952ad97513c10505d8c6d742571d88f1dcaafbf3262' 
  AND token = '32KK6+7ExpQlQcwheAGunQETDWJ1jKzGmwtCqt76D1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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