SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b71abdab41fc6fafba8f7244d704e811478432d4cc820153ec433b09055b2361' 
  AND token = 'dKyOzDKlqkB3VeN3q+vJiIoUJhaA5gBbolThHOzASJU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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