SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a52b57d226db908534e77879e2aaf6b435f393eb73616132039536e4554cb1ce' 
  AND token = '5EuP0DMtn+E9Q2x9In0TgwNOdNAYjDgqC/+i3OC9vxQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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