SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3eb6359d3116cfedacec014cdf01d7e2a6311f1c855cbd535377213455f55ab5' 
  AND token = '0ibwAf/M6AeBjOLwBYcioz1hLtjq+0F5fzWXM3vzhms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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