SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '50deaba9c92f5326addc4f9482147d7c2c36e463f295d879a7405e5647cb85ef' 
  AND token = 'DgGNMkFMQiREOjJHLI/2He1sLCS6BHAucoMlj8jzg2w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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