SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '73723a24c570db656a766f8de946c290cd06212fd071ea4f9c226ff6f3f71ad3' 
  AND token = '+UFBePxpq3Ib2Kn2aRpSNqp2BbkyoM/YVNgPMhD5gsY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

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