SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'df3fd4043bc17966305c757381ee2f1dab3662e537a31a4078eb9dc274d60067' 
  AND token = 'NOaQTIbVFO6xvs6fUW7zP6TKUpU0Ow0rouHMTQCETQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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