SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac724ea9f94162ee4541dbc000b0f0427fcb845ddf79bc66a0c73f5156a09d3c' 
  AND token = 'uwTrWzyGD6MgJwTgMsNej3QB/6bz1jVIJdTE+WnpRis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

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