SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9f4975ae3e5f2c602f7f644291de3f1a438a2aa4078d77b78db515879679261e' 
  AND token = 'tTY8qQaIqmb89M5vgrwhj+YtOKexUdkf6KsRQGtzdfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

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