SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'caf942d4e92e44b98a674d7c5722536a8ba62759574cfbdfe0a3c2531c06ec87' 
  AND token = 'Th12Exygfzs7zfVSDDfIRLoPwxiXqKwNX2z4I0lM5dA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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