SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8ffb6e795a7edcedafe4189b9fe411f88ea3144d5bbdbb94149f0423d835f43c' 
  AND token = 'CUYj9EqLK8Q42uM7Ul5x661kGK2gmAItazCkBGmPn5U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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