SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9967c4bde3501472a9fe886c100afd6a4255bbfa15d4ea3e25f8c2a86a24a9ab' 
  AND token = '3/3bD1bn4TO6r1EoaNqzSDy/9ZJEo3VKrGMry2/SJ0k=' 
  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