SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '0a07d769380025cafe50c3779dd1a1cd6c8fb3ae487a6e142233f23aba13c933' 
  AND token = 'rLBp2SOEc2KEm+yD2NaxLI0UYaskxpv1xjKy5T59WHo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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