SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ef78a6e0dae835862a7f18cadfd40f2d9d754f5414298856b273d0fdf82fffe9' 
  AND token = 'dfGNqjc5f8/dSK50GEtUDwjRD7nqXkz7EYNRq92Akg0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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