SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80699475de487edf3d44e69f1a08854cbd472968041e14a1df6e4b32c981512e' 
  AND token = '3hb2yIAAEZ+D/SsIKHJCl7FUyN0mllGaCmEgvnZTwB0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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