SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '855f9423412947d21855c15826f4b0757a9f7cd02500fffbc6a9d75a354a64c7' 
  AND token = 'tYetKQzDh6khjQmzmh7+rFlVwUoUbivC7zi1RiNjZto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00063

JSON explain

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