SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6f7d5227ed294e137b43170fbbed23bed54b3a4f5548e1ceb70b96f5025810b9' 
  AND token = '074/x/fGbx5zBbPyvwrGmo3DTWS10s8vzKA/79xrH3I=' 
  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