SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '37855ab445e61579f36b6c47f7e72cab7703023797490183ded3d4c1cd43a1b5' 
  AND token = 'gyGQOllgFxaDkR0I4r1Zwbx6q8zXDdRk+qkOj5NlFro=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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