SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8ca1ac28ec9535bd5abe8c5c25cfff4dbd83ae4c6af1b4a0d2c89a40cf91a6d' 
  AND token = 'OaVMFiQTazgHjz4zA5t0zUd4DfD+3I8Bj3PIQHRfodQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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