SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c703d139f191279758bf73d677de054b1dd00d7514c2d13ac3c7bdcc810adfe' 
  AND token = '5xcOoWO95rvud6bt/mSTZwaCvlYc4yIncsut+hDOTo0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00203

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