SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '53cfccf8f75e2c0c618f92010498fe971f6d8d314616e451232f00b8e3ca18b7' 
  AND token = '9BcZz/ZDbj6F9+RMAFFeX2EL73NAjTvVABybkc70M0I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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