SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '98b5927658007921edc6fb1c3726ed6690679298ebc0be950b661ebe9ead2d47' 
  AND token = 'P+XxaShX1tDSS2FUbhP1a2VQw/TJ6X94nAnIxyWrd1Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

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