SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'ac49701d194189de659c2bff2b4db4c88822d36197546652a519b7e5aa23d288' 
  AND token = 'IwFjyX828suG4qCC3OTGCfwpurtQgbZh+z6IZddK9z8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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