SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '79962dd7e560d1430da43a5178eae871875bcf9c2a61a336438144c71b594968' 
  AND token = 'VArhzCEH03YE6mQyirvWSkgVFrzaR5FL3SrTdEjDd3U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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