SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d3b388c772ce4c21d82d2f0fbf54da704ff4db31a4bba18dffbbb9c732f836c' 
  AND token = 'MnUfDi+LdRrH+bZAMb1SnucSVFV94DzGxxfmheATFy4=' 
  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