SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7246004c336632453b55de609a651387d444336449691b6e8cc3577ec56b0dfa' 
  AND token = '8gVB2YoIYfPe2wkkKBPLNhUg9bZzfhOdFRvK1f+YJPQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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