SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '790839fee6038c39ed2cfffbab104c5b17c9daaf06b6d630d0fb78ee622ee108' 
  AND token = 'HC06WBT/+cN5plp3DmsvYlQcpraGXllOkvjaVhqU6Iw=' 
  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