SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5b9db8ab9d92ced59370e739d282aaa1ebf459497266c074865c2c04b9d92804' 
  AND token = 'V/S8TiAPSpEF9nZhczjnIoWTyBhe9vJ6+YgECsBmylE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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