SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b5edc8687063f38ee4fb028cd01bad878e98a1eab74ca1d1cb5f86999cf0fbe0' 
  AND token = 'gtl5opCINIJFlo1/Z537utAISG1pt+OLqwVGE8T4Bdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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