SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '873aa0ec854a94fd560b28baa4df0f0f0737356c9a904bdd52d596034ff91ccd' 
  AND token = 'v3+hglU4wu2ArlfJUCtGjEGOF6siUHTwOJ6vMSZ3Ams=' 
  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