SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ef7eea2166f72dcf9b452cd2a318992c6f88ba178f3dc3ba99f4dee419e73d57' 
  AND token = 'Ub0glGfmUP0ZbVDnG9sBmLZjw//jrqnFDhCs6cowv1o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

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