SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '92c2fe4b1ed57c7d8b9a1a87d2debd785e638e4836a0371dda7335ecfbb85066' 
  AND token = '84Ye77Oy71DQtOdZTRVm+q2XK8S+c+sTWfu6jx4WvxM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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