SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'be50ac0fd21fed6a89fdf26e9febbe8725a9c33be709d528f9dedc0e99233eb8' 
  AND token = 'l9PLQdO9f9B7p7BuxSTJahxN11NL+KOIkw9Orj5fJKs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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