SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a3e2bd16b0d5d74ad18327768d714e2f3c27f4313e6452bd3e495afdcbc8e63b' 
  AND token = 'fP+FkNUL+2ZZ+sUs4Jt8G69ODQQlIGmUhXvshKoLkP8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

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