SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '29ef1929b31f2e717c9f6562005a7338fd397a5f2b150d50f759493de953b2e5' 
  AND token = 'lnYF0aoPaWGmYbrlZUNqI1jg/N7AMtQ060aSK+LBZvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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