SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1cb725d4fe4aa1d3032aa7efe1de8eb78bdcc7304849a6feb39ef1e93cc73d3' 
  AND token = 'QaSvVmo0YbUyk4pseND2Uq+cGR2oFaAzVCoSPo6SYSQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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