SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '343a74714337c8e2f90d568c10ea1aae8c20034e0fe03b6b72a015025a673a2a' 
  AND token = 'EdKVDgVFr1A3WRsxnjnWArFnVFzn79RRsCzUb2ALOrs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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