SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '7f54335770ca52f80786801d9d8a92bcb70f86772cc2f6babe2f7302c0b15ddb' 
  AND token = 'lxzMkHLxjhnV+/++9LFYXzN5NmZZHIeqaehv1HsFO7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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