SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6457043874145d5a4e34a5e9d8d9ad38472914b7c6ff50e40bdb0808debbbb87' 
  AND token = 'mTysg77GMijqtK6vJ3vWSiEpMA94rPqzYzFSirQiwT4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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