SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9d7b49d28895191ff1a187fb28b7073e2b64235b787e48559ebfa03a3ce15625' 
  AND token = 'w70lbf5echkzBmr4Cw8Oiep+hgDDzGHhGPkmWsZ2n48=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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