SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8640744925676ad84a8284bb44b12c0a56796027b9c4742c9a294d76d00d6f72' 
  AND token = 'U548459EIba/WjJ7HNTFlCYkOrJv8hCFYtfHTLnKydU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}