SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'af6198ff2a600db6267093b7a3e856918ce0c106b0f6d36ac5f73b8285e1a052' 
  AND token = '8s2Tpz7qgqqY9FQ3H2qGm+DazVYOO7kz2wGJGUL/MGU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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