SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f0c402944ae688aeb4fea294afafe20cab78fbcc067158e09d35643e21d9f3f7' 
  AND token = 'NFqRnP5bD/ZDGy/pETqBqcXMojqyr8npFuCioRW3tNY=' 
  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