SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbc95250bd4d8788dff92536a486d5b76c61a03db94fd483a5c1cfc1a445052d' 
  AND token = 'PV8Yxknr9LqNWDNAt4HSRZhXVBD+r2ZVPagBm7nsXEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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