SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5782c46c9f9a347cdace4df05948d258e5ad78a9c88b63bbbc8016c726b56171' 
  AND token = 'tVNyY5xY1MeRxZEcl9VNejvLbjdl92TKMEiQVOOxnaw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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