SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8fdb8a849f3209a25583f4366b39b9e77a450190566fed763371463e0f52751b' 
  AND token = 'hk1Q45fuWgBdhJ6dyWjQ6IqZV/bpQuHxc2ekXUrBlvk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}