SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3c0decf01a361dc41db7fb3f49b4cbe4210cbba34966f56af387b39288793d2e' 
  AND token = 'pexcc7PmnUMxPrBIZPI2urYD/IfCinTfVblFEr43lZs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

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