SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bf3fd3763b7af65ccec4084ff76b4d3e27840021e2c2d75e8980dee9514be930' 
  AND token = 'B3eZe1u3UiPfRk8Ze+47Qw9UVo6AiPydd4FxMfjiur4=' 
  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