SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac71e4f8ffebcf439ba95b02a5c41b1b054deb03e9c62e020db100bcc20945fd' 
  AND token = 'bUwSixFCBvoPqLH/hqT/X0kibXkNysUM2cdRyKvyY6c=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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