SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e8e0c32345b748402227301d8d347e64ed11a117d0b7ab6d5b9c094d2a3f429b' 
  AND token = 'PjkzquCnHB7cwnQBF5FIKWNjms9dqAqWomJMzUZi0IM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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