SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '935b28476bcd92ad4b341f7d1c58a8c1ceea91df03cfb3892811fbb8c4d8d332' 
  AND token = '3olaQLSG4llkhxQPQ5TNQAaLOJicbow1c1br/6Af1LI=' 
  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