SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '974c16b1418c0a026376e2e201e968fca727c431d062dd3ec5fafc30e99bdaa7' 
  AND token = 'mRopd7FJVInhVrHaddBkJtTS2pqgt2NMS2A+tt0gA/U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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