SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3bf6a891211e4e989891895efa5b9d9158299429f146bac368b84e562f0ec55d' 
  AND token = 'A8TXm/OYd6hyXVWjKdJHmOKKSuKKg0BipdmuPcsLV5A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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