SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9b2d685d4f8afcfb9306ecb0b99939ca9cb434e2b89e088cc5bd933da5780c96' 
  AND token = 'U33a7jUQLYm8vvZVnCbm0IE1qbtCUCOF/s4d3K3h4nY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

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