SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '1cabe81f0d1517163bb2a1b4139219c0691dfc437061dcedb037893336bad5b5' 
  AND token = 'y3YZ3lFtRVp9z0tBHks8WhHtZsMdwRDYx/0Tki4g21I=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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