SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5761344b8c56733c28b83d7269392d238eb3ba546617afc6616128667944beb' 
  AND token = 'tNV2zgJtpITY906f7CpkWA64pNrQF+7dCPWJIztWURk=' 
  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