SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '1f1a1dcfbc92e652a599c781538ece7122514fc3daa05d8375ced864d763d028' 
  AND token = 're7v88sGAumPczLQn58KyHm4687RPrrMnqae9eJtrmM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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