SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '08e5734535f129d7cc44b43d60b4ba513e6fe7f899df9b339a7621824b93d295' 
  AND token = '++qufTg2n0ZQqjPCGcRNL2D7XVITrI4XIhvQD9TcwzE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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