SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8012a5d1f192b6660462f8c972eb7672938619556a7ec697fde2c250adace885' 
  AND token = 'if3dXwFSvgDOF4K2lKRyc/6534AIfTzJEBqwPN6gBaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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