SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '27c75c91a5c8e9c9633c88a4bf4c195f405e37142df5055f00b7350f46d94574' 
  AND token = 'eJN/YjjfkQGpALC2jLLPcZzuaZmltbEY8Rq/aEqiof0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

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