SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '824523b228f3be9e9c3c283db4a642c23e85f6720ad2bb7588a39962a718fef0' 
  AND token = 'duRFlOD+SSRhJqTe3CcimJMPhWe0TKDFHLxnPC2QVuo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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