SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'd30f683261c7883f9997f947b9d2548b05afca2421bf48eaeb7793866b408c87' 
  AND token = 'egYyvGyhsTLYifCNvWUN0lOMyTy0leg1kApNf1y325U=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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