SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cb291721d504bb3cf35fd38e8ee7a41d6d7b310ee920c15c4b6e7becea7ca8d9' 
  AND token = 'OCpDeA1GoSuAZ4ZOJQx2lRTLcwuz8X8jtTKr+k50n7A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

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