SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6a9abfd506656b527b2e70aaf4ca3c2cb6a3cfce52ace6326c2b6a75783b58da' 
  AND token = 'F8PWRpVaAwX2akcgKF+8ABfHvRqi57u/fPc309WOmnk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

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