SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a7c2404a3941195f043bd5c28458f0b390615e253e32e529efc9db0e480d5bfa' 
  AND token = 'XtrMMnrwrW1MEJSYeAKX2pkBV0x21jh+2nPrmK/kw3M=' 
  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