SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'bde786b1fbd50e3fc3b83ebc113485b1c77aca607730385ed6cd2f7b94897464' 
  AND token = '6lHzqfxiRl+9WdxCEkAajxAIJ44BoqEvyfPYsIoVPQo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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