SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73da3c51e5faa905ae9f0ec60985360b0f7ec911377ff3c50f3d5f26828c22ce' 
  AND token = 'X68XdHUa+hqaKJ6+nuXQ1olOQJIOm6hsPy+r5/S4rIM=' 
  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