SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dd0cb2a0e99438f3cd39957ecaa326adf83c21f1d8890ee48b57ec24e7998a62' 
  AND token = 'IRu6loz7YVgUTruRsuSSBz2jjqC2jeFgUcjRDBPRpyA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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