SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '49a20a5849d43e632a2b0bed8080937a1a32b1c0e319748e9ffcefc73e0af999' 
  AND token = '8nEpYNRvGbusx+SM/fu/tayH2Qyq75LVud+QAPPGnME=' 
  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