SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6bdd5571f7300be66d153d506114ed988d1e40b3566e6d3a6e94ffe2ecebdbc1' 
  AND token = 'S/RhLiWzSR2M4UnKKK6ct8F+YSbtNF6FFrTS/H7o3uQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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