SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '803e05b95be8aef21765981b87c5cc4c437f94f12b7e4120fa643a7c8506402e' 
  AND token = '545fmcwM1SX+pORvEGAfG3R1+FvOieBqn23dCNQFj7I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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