SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dcba9a7ff3ec394849dfbe6899bb48b70505b6d1867dd31cabc27fd2df114b05' 
  AND token = '6nOs9xdnPfE7OK3RWukInlUXCChHHRcMYQwTNp9y3vg=' 
  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