SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6d015af094a4aa0933e72766bb81d78a6cd5df7971fe3cf923252153c3eb0b93' 
  AND token = 'WrnXIKMPR+tLle2D9m78ZRKhGXfT8VmmL84xvHfA4RQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00012

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