SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b9d586bf9cbb6a776d1053cdd35fc197a92bf801fa59c44ef4a9852732f806b' 
  AND token = 'AwgvfDiP6ghNXQYBRKAexp0o9IXOmx0O1r7hy1njYXM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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