SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '99a7692caf8b58d23a83a8fe14c38dff14967cde9906d2f6d812432b3f898758' 
  AND token = 'VNw+qodVDXynZ8poC0unBpZqHdm/AGaGlRzoHDvXse4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00069

JSON explain

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