SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f57dcf42d6328ee7209bfd73bc128a331d773cf0eab149b268ac190dcb39b97a' 
  AND token = 'y2ZGUiYqIZCobHG22V/uNT/D4/tIpZBlwa01CiAmjaQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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