SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '42349fccfaa88a8f611545700cc8464411b18d746d403fa1d0caca7cc971d168' 
  AND token = 'CUd1x+uKbga1G6FkmmXIIx/SqE8DOUDAAMD9ENeS+Mc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

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