SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3ff753691aca51de9a8f410a3fa3fffc60787c53a17549f3c4027a1c9fcb3b97' 
  AND token = 'm+mxHID7TVyqQVvyUPq/CAyzAYIHWOlS3jYeA52GnFI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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