SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '644a4cd820f795a815c297e50341dec1b68382184c87bae37f2b7ea4f5cc84ff' 
  AND token = '0QJjK9wqay7+A0c/tGSzImt5zvNt68qAZf1SoZaW/Lg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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