SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cff1dbb799667182a125344c9aeeace44d0dd0e23bae0bd190a33087a1c55af9' 
  AND token = 'Tdn5i6el9+O3iNLBiaxKUeHFc7pk290LBKTHeod0GM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00013

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