SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '35c2ec51b84ea611e0055b943c8202e0c314101a4853ab14487752a5f6cc24de' 
  AND token = 'SrWsnl+UvXTpQ8LIEjMnvha55OCoDK45rTBtA36FDR4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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