SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '818ae10d583988768e1d456009d2b0a50834be42822cd29379fc5abafedcc2f1' 
  AND token = 'sk2fYvG9u5SiukJP9/EH7oHeW0//m4naS1Yh5AwdtYk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

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