SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'cb6b51c4749ca319e63a5971ce31e849933e40359dfbc55dc09a8f515e10018a' 
  AND token = 'tDQo0w6S0GfNS+SWXSDrjgO+AIUPRta6HzAI/o6kqXA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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