SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5aa9fa2a153a1105a78e51c2d55641bddddec24348836dccce5426f8571c7ee' 
  AND token = '0Lb6I+w1ndF1tjj3XsQ20lZARs5GOlsdaO9zKTW04rI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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