SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b9a6dde081d08ccf4cc4d17b19ad53a416d86210dc10d84e746cfdcab9d72da8' 
  AND token = 'McgEzHZIyk5EJequB9I9o29E0uyDRZUIIekfA1twQRw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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