SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd73ad5865fc878f2acd37d6dd5e75e7f72d28cd4278d9f69f9f5cf77659cccd3' 
  AND token = 'RsHRAyNei2zJxZ8iVszalmP7hZGreUO5XPRibkVq0Nw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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