SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76c422923767740ea88d65605289207ca617a92f571b03e19f151566bea47f32' 
  AND token = 'pC4n6IYuIiwNWhol+7owOz++spkoJw3o5VZSWDMP4p4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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