SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '12b14e75a2e4cba8f97f5e814872d433e175d702f61e5780ba68ac54c63e9e76' 
  AND token = 'pSjh1reMHr3EClNXfJBCTVvgIqn7FvPYa8LroY5RXEg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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