SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '75198d9078cd5c09015333f3e161809d1ef041318ef47419610aa1add764867d' 
  AND token = 'w7aphVsuLr5dTJB8ZimSlwo5WLcJLEAfvdDKQbG57hQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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