SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '9d577bcc0fb182355f551c1b051c37c28ecd04920dd989950c9d56fde94d3fb7' 
  AND token = 'bayzQGKkAxn/pJiJtZu3VnhLv94PHtQ3muLo2PZ6854=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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