SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b8b7c565cea1eca2218fa5bdee7fce479fa8eb668eea124bd7ad861c692326be' 
  AND token = '03JQOETsvJ5GvHr+KW8aY957Oa6tQNFY4NxMPkUAwqI=' 
  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