SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7667b642afa57c3def47118422dcff4a782b7be5cb114581a95db74c9bb6d0fe' 
  AND token = 'QrFC+ig1CAAhBe8ljzpzzbqeJ4IuLpjMy2RW8vTa8CU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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