SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '924aa6a2da7af43c21856befaca8996e9978160c132ab3035ba5d385980184e4' 
  AND token = 'GXc9A3PLcj3ZjCpbCtKlG/HUOF37dQouPbSViqrZhwM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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