SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b3df59e1227e820638230b2aaee27c918f1fc8285d3fade5ca8827bf97a5ea81' 
  AND token = 'HFatsrBp/5sMtIMHGn606nVYPlPsD1OnCHneDo/3FdY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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