SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac4badb5af91ebe2dc1d53ac45889f1472365b92906584b4ee1210445dfce583' 
  AND token = 'm+VIJ0X9ScB6+/5HppSYUjKRtxaZ6Wyc/1FbdNeKt1Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

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