SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '79351554b4b41d70bef69528b33a1e8b88766cf9cced3ca7d3f1cd8c0eaf2d7d' 
  AND token = 'Mw431W4wblYZOotU6WvDGQ+ii3SedDgJckeIiWSe+xA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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