SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f75e6b1740291aa066254be7d17a49b65e6f48aa9f50261addefb6015a4936a6' 
  AND token = 'j+rKAdT66gjbdh5/g5mWwkS5C6pJHPSBKqk7Eo420sM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

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