SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c308314ec3751b4a3512420965db3bf48151bfdb2e9e1d90e2df05073720fc77' 
  AND token = 'VBvR9Lop87VsKjCeYAYnG2niMILE+01pKUcpWFIP0u8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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