SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f8a502939c27b8facb6ba4d7015e4741e978b8365cf97f14f2356686dd43c578' 
  AND token = 'P/K/j9dxs29/PrsG5PrDJjyahZEQvbUJE+SEXewlmtY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

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