SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '76cadaacfb0570da23861c3dd3c64cd39f7d684f840fae849fc443f3a91ff396' 
  AND token = 'qYIm8kA/CsmaUuW2lBmgFNNMFDqUIStXWFmA9M+cUlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

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