SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '17b6332c63dd831f4216d6bf6f6152f5ec52d5bee488cd5af2dbe7cfdfdb7822' 
  AND token = 'CxLy29Tjhgd+ddjgGDBTVwDczv6SpJQiwJlyoUoW53Y=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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