SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b3fed4946123f8ee685cabbf3fe8f401039ad80eff9897184dcf5bb55d57f635' 
  AND token = 'TXtNT2kcSuKO1BpRY9TDNrFAfiFssWqGChFFAxM1yaE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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