SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '0a308464633b5149b065ba90234130694ced3e01417ec8e675627c84959fb84d' 
  AND token = 'b3CZpmFVJEpiJtQnq7yNlY6OHoXQ0wVdJ/dEcxPnTZo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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