SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '33cb497dac8ef9f6114919b5c6fbf5cbdfee82e4a03653db7ff8a067f5db76da' 
  AND token = '+5OUvL8iNzm40glrqXU8OVojWS6/d8Yoz30IFgoJ3Z0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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