SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9c5d705f68a9d46b80471c8fadd64ffcfc2afda3fcda9a03e0ba70aef3975a4c' 
  AND token = 'h6vZ5UjVa2ynzxJPZ5BbkEmDkrXaah6O+bqMtofJkdQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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