SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9ad944d5d2ec7770f41efc395010f0cdda9bf052e066123df63e32fb65f93b9b' 
  AND token = '1gwVNUyaHkKeYOXTZ+wrcstYuFuzqKzWGvzjmVAwnf4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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