SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '29a2053b8ea7f772c29b7765cf94a115326e92a4369363571cb509e52fb0a5be' 
  AND token = 'mtzgwS6bgqhNpaUgfCsmeQko+NE297I4bKPirFa14zA=' 
  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