SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = '636ccd5c012d581a2eed83d6ca662ac72e3d7c0c29ed9b61c2c1c70aa4bb5129' 
  AND token = 'LfmkWl2GokiCVSH2OJbJqiH/LY0YjrIZ3fEbR5kRJto=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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