SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec756426954810e332811e4b1d21d3e7ff419220cdfe17a7f9e6ba70a7bdbaff' 
  AND token = 'SwW+cl4KFJwv3314c6wc1iypF5H+YUdwk34Dt6cHcpY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

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