SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b25529a01568cebe1b7fd062f6456e7f432a77f7bde933978ab769812ca15620' 
  AND token = 'EGFG8p2GVXkxfyVEGd1NNaciQvm9AXPSGu4uON9OUvo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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