SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0503e0b81872fe268611412fe798c967eceed411d784d8b647212a6aa6868bf' 
  AND token = 'U2ivQqbO7ngGU0mYNWQrtrrwkx4ZqTW8PLn9tS0KCoA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

Explain
id select_type table type possible_keys key key_len ref rows Extra
1 SIMPLE Impossible WHERE noticed after reading const tables