SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecb90f1596122adae649a9a7ad5ca5c1adb4d5255bf2f970b0ff37c9cdbdea7d' 
  AND token = 'bJg+9hqCx4Bnh703oWjzRXwCVPfEnQM3/U+Jp3WarIQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

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