SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79b10ab9abfb12451f78971282e0517519850d11d6a77253a1a478ec3d6b9873' 
  AND token = 'IDYbu2QWs8AOZghf9FXtC2jQpd+TPkVeWCqut/czzs8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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