SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '93d7ad567b497922e213467b087d062e51b39844f1ccfa662a98a030dd497aed' 
  AND token = 'YVuL6m6IIiaPfv3ZcRpfYjVjqXRi0hYDbL2ozKfuyCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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