SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '350887d02f944b1cabeeda6719f384388650fa9116d4e4ef6d86270e53864c57' 
  AND token = '3rskqjPnq6QRReKU+Sl/NaIcD7qqI1Kl0wO+zDrNpvg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

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