SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '98912f4721be46ca04b177467b6732173879f6ab743f716bac68ee2b8607928e' 
  AND token = 'qAASoXWRUNE4Bh0GusNK3KRZJzZFT3VJKVuTBAW/J+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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