SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b28be750a6b61c294d99344a16a50d8b3694097f83a395f94e2d641762eac667' 
  AND token = 'YCKiipr7d2fu55g5D/+k2X+ARmr+SA3tcFdfFDQ1Kcw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

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