SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1728e47265a3ece0e07ef06a58542c24cd5dcbe7f082a274e61a59bedb64eca9' 
  AND token = 'pfVhBZJH4s/BiU5Ru5jQ2QWMiOvNu3C+mB2YTbqrbvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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