SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5085a34b1f02145d893e63056daf9545da2e26474e6421cbe8afd77b7340e16b' 
  AND token = 's2UuQkrGTpI72jLv+GHbe4DtsTWIUZrNE+CzL//XRVg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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