SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f6227d0cc932dd018725a61aa9d3c51c1af9080cc8442cd12ddffb51bfd9b969' 
  AND token = '87dxY6EtFsseCgNVtgJJRN9xkY/SXD+Ajalc3b8YFWk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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