SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '68af212d7292eb75f6bcda015b5f4c1e20517c9e4180c26a9d7f89ec427dc0b7' 
  AND token = '6W/aNsBrw3ubOa9VLWkgcLOfmtz6RBRZG/xupCzM940=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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