SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8aab8b3e144f908819757322af435da3eda566453e2154b132f73eb6ef8bad15' 
  AND token = 'OCjKv5iENFK70TGX42qPZIOib03o9XZfLZBjlVWbjbI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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