SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '84d3ebd88b2cf49c6acf6b8f4b0618a1f8b8a1615dbec5a0d592c45bcd38b533' 
  AND token = 'K+doOqcrwX7yLmGamRXGkO/rTHilP+QaHfLcbx9Oc4I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

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