SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a6fc78037d2d591bf648f8581a67042d8faa03d23a9878a22a57dce31268065' 
  AND token = 'BXsTmptGGQelXHAKxEFNUORgvFMqUpYxWZht1cdjNXY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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