SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '97198861b84213106b0e3aaf57f34f002bf76ffea19edf4e536b638053fce71f' 
  AND token = 'jekdidvlRYsd2cfIb9q5qjEQQ9w/Au0N7lRNuG7oMrc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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