SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8a3d43cbe567e915a9c8ed316285580d21a52fa9c239341d6beeb69cd60a9bdb' 
  AND token = 'BV7CDpdkJi1nsiHVv0QehGUlwxaLBIjKjzvo4ykJrpo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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