SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'eba7da9526c82854ac00e4cccc5be69730624c1ccd86eb8f29c0bf2143ca19f9' 
  AND token = 'cEDKZNrb+hnGqUQPVlDTMiEa6ZWEwcMbbh6xpHnQf0A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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