SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b43cfb8982df9bd2641980a6a34a9450cc029cf5fe2d0bd4810c1f3deba27b66' 
  AND token = 'rd3JeHeRelTIm08hIhsfegtB1/GFmfphMjC1gPRkHdk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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