SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b7a3239920d0522b49f82430947558e75b097f27a5dacce1f91425ddc316e53' 
  AND token = 'DMzQWw4+Azm+Zp3D0QnK2q/o9xzsuB9WVJxTgJdbfrg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

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