SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '621786f1a205e6995abff5ede3a7bc7676f73f908ec941dc5f1fbb7cebb6ad53' 
  AND token = 'rybealp0kgfpvCczWZ7eKpkk5xPZylV6MEjJA/lBxgo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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