SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '520b9f65fbca2329c39705142a5442f29dae4d75dda4932360a25046584825bd' 
  AND token = 'ywh1fo0/RzteqzqfLGmyKaqKotcYy0oNozGKIk7dwak=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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