SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd656980b85c5c77318275e38c95a6f532b8162fe1f1d7ddc174f2aefec7eb69a' 
  AND token = '3qr1jbSBrmhxffLeaNQvsr1gZSdhwybtuRYa1CBuLuk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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