SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f02a538a8e441729364870152eba6501ddbf22be07907e4ce6e65115ae90c2c' 
  AND token = 'qK1+mMKtQLTRIeqajD1QIqco4l44cOErpZUK6GcbeOM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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