SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a43469c84e0bd7583182c53534ee538606266be1f31f801a200390655627f652' 
  AND token = 'upNjfJ/gKD5HI20ca8MYZlIzw6UwXsOYHpS4VJDqx4Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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