SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a2da5e5547bdaeec078c06356f0c4ba47cb701285e750920d1ef758481f7928a' 
  AND token = 'iLEXijDPbl1Tpmd0/Z9qxYHdnhxFAJoHAw3n/4lQmM4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

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