SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e63abe9d9daadb28c4a00ffeebc3e432f55e3e24bcb16a8010d41d047ee72a16' 
  AND token = 'kFn3XN37cyiyu2qHFzdj8oZw+XSHB+xfWKDkza0JkzI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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