SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9d750e397650bf235352fe04fcf2108c7fd2269bd5935c5cd04a42ebbe7fe167' 
  AND token = 'bf0ZwltGhRuzA9D3uqYbYt7F2We4AhcGUYxU35Mpti8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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