SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2c6d510e6663e353c960f66db32ff9c7547544f4e2b0e8263c23a98b81ff6ce0' 
  AND token = '5vn/KdvscxpB88k/Oa1+ZXGbQUWh+cpRaiBZwpkq5PA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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