SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e8d54d1041999a6157ecf744aca1471690bd32619c7a2f17607e79615d45a3dc' 
  AND token = 'FI8VYGMddt5mIS1eOhO94u+lZXb8QrkUPLzKTiQa5z4=' 
  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