SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd17f58efaaa09373d8d0cc72c78686a977d05e1603e46dac85d48eb52c57f9aa' 
  AND token = 'YbJ5qIV6vOVTplVaS2mYYkx9YNTVPswKTPr+qmngStA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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