SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48021c5302bdba317becad00c8afca071ff636580133d46b85ff63a0114b07db' 
  AND token = 'agoOaAYlCPwtBU2T33pmkfm9VDQqrAgnOBf57GOqC34=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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