SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'dbbff9f513b23fc9259e4591e3052f4ae4590d9173d625c3506b67251c8a53c6' 
  AND token = 'd8QER2ES7Ak5hgTJKPtuc9xJxCwwWScI5gWSxTCBXIM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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