SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'abc43a0a0b540c1bed5beb1efad479fad3194c31dedbdd85c79e246c5e127fde' 
  AND token = 'vchbfWAKIUVPhC7gs5Kzpnq4AktBs3g6lR9g+KaJTHc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

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