SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '841c8fd174d49143d97da2fce6c1cb89de3f9658b3241217293d6a72e70d9483' 
  AND token = '8+ybRDUB12VtB9utDOeTGPD8Q4jf3hMmaO2zgh65hb0=' 
  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