SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '36ca0826f8929e3fbe29bb42f247d1d318ebc786861524784af62b127b62a095' 
  AND token = 'BK4JxYM9RX6F9VounvkGB/tkM0pdRsu6rYVaAepzJmg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00045

JSON explain

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