SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c2f0bf4c234eef5407a35e2d875da94c3f275ade16e67a9863c3e9a98d17ab1d' 
  AND token = 'D5VlXt12lUtSrBK75nbQtxmZaZ+sR4gDFTbtPail3u0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

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