SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '18522943e42e6816c185f73973f6b2e250f4455cdfb2211ba18796e60d4df5ff' 
  AND token = 'AlHl6GrcLkIaQnDydjf+QPEQMb2WtDxbf6S6nce6ok4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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