SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '82690ce23e40671026943e11222b80586edba46234e28de0f8504fe050619ea4' 
  AND token = 'ow936zSPUYD/QkpmNAmRDV+Z7OnBnKMjWCGueIKKzXo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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